diff --git a/Cargo.lock b/Cargo.lock
index c071a2e11d269..9be1cbcec461f 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -5,6 +5,15 @@ name = "adler32"
 version = "1.0.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "ahash"
+version = "0.1.18"
+source = "git+https://github.com/tkaitchuck/aHash.git#91bcb84a5cee8dfc7782cc815c3c7f9c1b88badc"
+dependencies = [
+ "arrayref 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "const-random 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "aho-corasick"
 version = "0.6.9"
@@ -19,7 +28,7 @@ version = "0.0.0"
 dependencies = [
  "compiler_builtins 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "core 0.0.0",
- "rand 0.6.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand_xorshift 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -88,6 +97,11 @@ dependencies = [
  "winapi 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "autocfg"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "backtrace"
 version = "0.3.11"
@@ -513,6 +527,24 @@ dependencies = [
  "winapi 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "const-random"
+version = "0.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "const-random-macro 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "proc-macro-hack 0.5.4 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "const-random-macro"
+version = "0.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "proc-macro-hack 0.5.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "constant_time_eq"
 version = "0.1.3"
@@ -522,7 +554,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 name = "core"
 version = "0.0.0"
 dependencies = [
- "rand 0.6.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -576,7 +608,7 @@ dependencies = [
  "crossbeam-epoch 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "crossbeam-utils 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.7.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "rand 0.6.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "smallvec 0.6.7 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -942,6 +974,11 @@ dependencies = [
  "byteorder 1.2.7 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "fuchsia-cprng"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "fuchsia-zircon"
 version = "0.3.3"
@@ -1230,7 +1267,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "libc 0.2.51 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
- "rand 0.6.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -1799,7 +1836,7 @@ version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "libc 0.2.51 (registry+https://github.com/rust-lang/crates.io-index)",
- "rand 0.6.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc_version 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "smallvec 0.6.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "winapi 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1946,6 +1983,16 @@ dependencies = [
  "log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "proc-macro-hack"
+version = "0.5.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "proc-macro2 0.4.24 (registry+https://github.com/rust-lang/crates.io-index)",
+ "quote 0.6.10 (registry+https://github.com/rust-lang/crates.io-index)",
+ "syn 0.15.22 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "proc-macro2"
 version = "0.4.24"
@@ -1978,7 +2025,7 @@ dependencies = [
  "lazy_static 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "num-traits 0.2.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "quick-error 1.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "rand 0.6.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand_chacha 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand_xorshift 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "regex-syntax 0.6.4 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2067,19 +2114,19 @@ dependencies = [
 
 [[package]]
 name = "rand"
-version = "0.6.1"
+version = "0.6.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "cloudabi 0.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
- "fuchsia-zircon 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "autocfg 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.51 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand_chacha 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "rand_core 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_core 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand_hc 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand_isaac 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_jitter 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_os 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand_pcg 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand_xorshift 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "rustc_version 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "winapi 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -2088,7 +2135,7 @@ name = "rand_chacha"
 version = "0.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "rand_core 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_core 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc_version 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -2097,12 +2144,20 @@ name = "rand_core"
 version = "0.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "rand_core 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_core 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "rand_core"
-version = "0.3.0"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "rand_core 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "rand_core"
+version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
@@ -2110,7 +2165,7 @@ name = "rand_hc"
 version = "0.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "rand_core 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_core 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -2118,7 +2173,30 @@ name = "rand_isaac"
 version = "0.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "rand_core 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_core 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "rand_jitter"
+version = "0.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "libc 0.2.51 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_core 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "rand_os"
+version = "0.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "cloudabi 0.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "fuchsia-cprng 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.51 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_core 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rdrand 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -2126,7 +2204,7 @@ name = "rand_pcg"
 version = "0.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "rand_core 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_core 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc_version 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -2135,7 +2213,7 @@ name = "rand_xorshift"
 version = "0.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "rand_core 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_core 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -2159,6 +2237,14 @@ dependencies = [
  "rand 0.4.3 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "rdrand"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "rand_core 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "redox_syscall"
 version = "0.1.43"
@@ -2262,7 +2348,7 @@ dependencies = [
  "num_cpus 1.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "ordslice 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "racer 2.1.21 (registry+https://github.com/rust-lang/crates.io-index)",
- "rand 0.6.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "rayon 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "regex 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "rls-analysis 0.16.12 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2683,6 +2769,7 @@ dependencies = [
 name = "rustc_data_structures"
 version = "0.0.0"
 dependencies = [
+ "ahash 0.1.18 (git+https://github.com/tkaitchuck/aHash.git)",
  "cfg-if 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "ena 0.13.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "graphviz 0.0.0",
@@ -2690,7 +2777,6 @@ dependencies = [
  "lazy_static 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.7.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "rustc-hash 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc-rayon 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc-rayon-core 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc_cratesio_shim 0.0.0",
@@ -2759,7 +2845,7 @@ version = "0.0.0"
 dependencies = [
  "graphviz 0.0.0",
  "log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
- "rand 0.6.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc 0.0.0",
  "rustc_data_structures 0.0.0",
  "rustc_fs_util 0.0.0",
@@ -3283,7 +3369,7 @@ dependencies = [
  "panic_abort 0.0.0",
  "panic_unwind 0.0.0",
  "profiler_builtins 0.0.0",
- "rand 0.6.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc-demangle 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc_asan 0.0.0",
  "rustc_lsan 0.0.0",
@@ -3442,7 +3528,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "cfg-if 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.51 (registry+https://github.com/rust-lang/crates.io-index)",
- "rand 0.6.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "redox_syscall 0.1.43 (registry+https://github.com/rust-lang/crates.io-index)",
  "remove_dir_all 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "winapi 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -3689,7 +3775,7 @@ dependencies = [
  "futures 0.1.21 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "num_cpus 1.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "rand 0.6.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "tokio-executor 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -4008,6 +4094,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [metadata]
 "checksum adler32 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)" = "7e522997b529f05601e05166c07ed17789691f562762c7f3b987263d2dedee5c"
+"checksum ahash 0.1.18 (git+https://github.com/tkaitchuck/aHash.git)" = "<none>"
 "checksum aho-corasick 0.6.9 (registry+https://github.com/rust-lang/crates.io-index)" = "1e9a933f4e58658d7b12defcf96dc5c720f20832deebe3e0a19efd3b6aaeeb9e"
 "checksum ammonia 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "fd4c682378117e4186a492b2252b9537990e1617f44aed9788b9a1149de45477"
 "checksum ansi_term 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ee49baf6cb617b853aa8d93bf420db2383fab46d314482ca2803b40d5fde979b"
@@ -4016,6 +4103,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum arrayref 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)" = "0d382e583f07208808f6b1249e60848879ba3543f57c32277bf52d69c2f0f0ee"
 "checksum arrayvec 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)" = "a1e964f9e24d588183fcb43503abda40d288c8657dfc27311516ce2f05675aef"
 "checksum atty 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)" = "9a7d5b8723950951411ee34d271d99dddcc2035a16ab25310ea2c8cfd4369652"
+"checksum autocfg 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "a6d640bee2da49f60a4068a7fae53acde8982514ab7bae8b8cea9e88cbcfd799"
 "checksum backtrace 0.3.11 (registry+https://github.com/rust-lang/crates.io-index)" = "18b65ea1161bfb2dd6da6fade5edd4dbd08fba85012123dd333d2fd1b90b2782"
 "checksum backtrace-sys 0.1.27 (registry+https://github.com/rust-lang/crates.io-index)" = "6ea90dd7b012b3d1a2cb6bec16670a0db2c95d4e931e84f4047e0460c1b34c8d"
 "checksum bit-set 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)" = "6f1efcc46c18245a69c38fcc5cc650f16d3a59d034f3106e9ed63748f695730a"
@@ -4046,6 +4134,8 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum commoncrypto-sys 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "1fed34f46747aa73dfaa578069fd8279d2818ade2b55f38f22a9401c7f4083e2"
 "checksum compiler_builtins 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)" = "a28c3898d0c57b26fa6f92de141ba665fa5ac5179f795db06db408be84302395"
 "checksum compiletest_rs 0.3.19 (registry+https://github.com/rust-lang/crates.io-index)" = "56c799b1f7142badf3b047b4c1f2074cc96b6b784fb2432f2ed9c87da0a03749"
+"checksum const-random 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)" = "7c430a6c6170b741ced6334950903f1cfd27385ce0bf80fb22561b636e09e089"
+"checksum const-random-macro 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)" = "cdf38483934c41305eaf335e39d77f1803ed553ffbf4533746a51a14a41158c5"
 "checksum constant_time_eq 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)" = "8ff012e225ce166d4422e0e78419d901719760f62ae2b7969ca6b564d1b54a9e"
 "checksum core-foundation 0.6.3 (registry+https://github.com/rust-lang/crates.io-index)" = "4e2640d6d0bf22e82bed1b73c6aef8d5dd31e5abe6666c57e6d45e2649f4f887"
 "checksum core-foundation-sys 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)" = "e7ca8a5221364ef15ce201e8ed2f609fc312682a8f4e0e3d4aa5879764e0fa3b"
@@ -4091,6 +4181,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum fs2 0.4.3 (registry+https://github.com/rust-lang/crates.io-index)" = "9564fc758e15025b46aa6643b1b77d047d1a56a1aea6e01002ac0c7026876213"
 "checksum fs_extra 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "5f2a4a2034423744d2cc7ca2068453168dcdb82c438419e639a26bd87839c674"
 "checksum fst 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "d94485a00b1827b861dd9d1a2cc9764f9044d4c535514c0760a5a2012ef3399f"
+"checksum fuchsia-cprng 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "a06f77d526c1a601b7c4cdd98f54b5eaabffc14d5f2f0296febdc7f357c6d3ba"
 "checksum fuchsia-zircon 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)" = "2e9763c69ebaae630ba35f74888db465e49e259ba1bc0eda7d06f4a067615d82"
 "checksum fuchsia-zircon-sys 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)" = "3dcaa9ae7725d12cdb85b3ad99a434db70b468c09ded17e012d86b5c1010f7a7"
 "checksum futf 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)" = "7c9c1ce3fa9336301af935ab852c437817d14cd33690446569392e65170aac3b"
@@ -4194,6 +4285,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum precomputed-hash 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "925383efa346730478fb4838dbe9137d2a47675ad789c546d150a6e1dd4ab31c"
 "checksum pretty_assertions 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)" = "3a029430f0d744bc3d15dd474d591bed2402b645d024583082b9f63bb936dac6"
 "checksum pretty_env_logger 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "df8b3f4e0475def7d9c2e5de8e5a1306949849761e107b360d03e98eafaffd61"
+"checksum proc-macro-hack 0.5.4 (registry+https://github.com/rust-lang/crates.io-index)" = "3e90aa19cd73dedc2d0e1e8407473f073d735fef0ab521438de6da8ee449ab66"
 "checksum proc-macro2 0.4.24 (registry+https://github.com/rust-lang/crates.io-index)" = "77619697826f31a02ae974457af0b29b723e5619e113e9397b8b82c6bd253f09"
 "checksum proptest 0.9.2 (registry+https://github.com/rust-lang/crates.io-index)" = "24f5844db2f839e97e3021980975f6ebf8691d9b9b2ca67ed3feb38dc3edb52c"
 "checksum pulldown-cmark 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "d6fdf85cda6cadfae5428a54661d431330b312bc767ddbc57adbedc24da66e32"
@@ -4205,16 +4297,20 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum racer 2.1.21 (registry+https://github.com/rust-lang/crates.io-index)" = "37c88638777cc178684cf648ca0e1dad56646ce105b8593dfe665c436300adc3"
 "checksum rand 0.4.3 (registry+https://github.com/rust-lang/crates.io-index)" = "8356f47b32624fef5b3301c1be97e5944ecdd595409cc5da11d05f211db6cfbd"
 "checksum rand 0.5.5 (registry+https://github.com/rust-lang/crates.io-index)" = "e464cd887e869cddcae8792a4ee31d23c7edd516700695608f5b98c67ee0131c"
-"checksum rand 0.6.1 (registry+https://github.com/rust-lang/crates.io-index)" = "ae9d223d52ae411a33cf7e54ec6034ec165df296ccd23533d671a28252b6f66a"
+"checksum rand 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)" = "6d71dacdc3c88c1fde3885a3be3fbab9f35724e6ce99467f7d9c5026132184ca"
 "checksum rand_chacha 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "771b009e3a508cb67e8823dda454aaa5368c7bc1c16829fb77d3e980440dd34a"
 "checksum rand_core 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "1961a422c4d189dfb50ffa9320bf1f2a9bd54ecb92792fb9477f99a1045f3372"
-"checksum rand_core 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "0905b6b7079ec73b314d4c748701f6931eb79fd97c668caa3f1899b22b32c6db"
+"checksum rand_core 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "7a6fdeb83b075e8266dcc8762c22776f6877a63111121f5f8c7411e5be7eed4b"
+"checksum rand_core 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "d0e7a549d590831370895ab7ba4ea0c1b6b011d106b5ff2da6eee112615e6dc0"
 "checksum rand_hc 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "7b40677c7be09ae76218dc623efbf7b18e34bced3f38883af07bb75630a21bc4"
 "checksum rand_isaac 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "ded997c9d5f13925be2a6fd7e66bf1872597f759fd9dd93513dd7e92e5a5ee08"
+"checksum rand_jitter 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)" = "7b9ea758282efe12823e0d952ddb269d2e1897227e464919a554f2a03ef1b832"
+"checksum rand_os 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)" = "7b75f676a1e053fc562eafbb47838d67c84801e38fc1ba459e8f180deabd5071"
 "checksum rand_pcg 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "086bd09a33c7044e56bb44d5bdde5a60e7f119a9e95b0775f545de759a32fe05"
 "checksum rand_xorshift 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "effa3fcaa47e18db002bdde6060944b6d2f9cfd8db471c30e873448ad9187be3"
 "checksum rayon 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)" = "80e811e76f1dbf68abf87a759083d34600017fc4e10b6bd5ad84a700f9dba4b1"
 "checksum rayon-core 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "9d24ad214285a7729b174ed6d3bcfcb80177807f959d95fafd5bfc5c4f201ac8"
+"checksum rdrand 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "678054eb77286b51581ba43620cc911abf02758c91f93f479767aed0f90458b2"
 "checksum redox_syscall 0.1.43 (registry+https://github.com/rust-lang/crates.io-index)" = "679da7508e9a6390aeaf7fbd02a800fdc64b73fe2204dd2c8ae66d22d9d5ad5d"
 "checksum redox_termios 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "7e891cfe48e9100a70a3b6eb652fef28920c117d366339687bd5576160db0f76"
 "checksum redox_users 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "214a97e49be64fd2c86f568dd0cb2c757d2cc53de95b273b6ad0a1c908482f26"
diff --git a/src/librustc_data_structures/Cargo.toml b/src/librustc_data_structures/Cargo.toml
index 63e44d82a28c3..c47952fa9a4d2 100644
--- a/src/librustc_data_structures/Cargo.toml
+++ b/src/librustc_data_structures/Cargo.toml
@@ -21,7 +21,7 @@ cfg-if = "0.1.2"
 stable_deref_trait = "1.0.0"
 rayon = { version = "0.1.2", package = "rustc-rayon" }
 rayon-core = { version = "0.1.2", package = "rustc-rayon-core" }
-rustc-hash = "1.0.1"
+ahash = { git = "https://github.com/tkaitchuck/aHash.git" }
 smallvec = { version = "0.6.7", features = ["union", "may_dangle"] }
 
 [dependencies.parking_lot]
diff --git a/src/librustc_data_structures/fx.rs b/src/librustc_data_structures/fx.rs
index a2afeffe73050..872425ab03689 100644
--- a/src/librustc_data_structures/fx.rs
+++ b/src/librustc_data_structures/fx.rs
@@ -1 +1,10 @@
-pub use rustc_hash::{FxHasher, FxHashMap, FxHashSet};
+use std::hash::BuildHasherDefault;
+use std::collections::hash_map::HashMap;
+use std::collections::hash_set::HashSet;
+pub use ahash::AHasher as FxHasher;
+
+/// Type alias for a hashmap using the `fx` hash algorithm.
+pub type FxHashMap<K, V> = HashMap<K, V, BuildHasherDefault<FxHasher>>;
+
+/// Type alias for a hashmap using the `fx` hash algorithm.
+pub type FxHashSet<V> = HashSet<V, BuildHasherDefault<FxHasher>>;