Rollup of 6 pull requests

[Centril]

Successful merges:

• rustdoc: overhaul code block lexing errors #56884 (rustdoc: overhaul code block lexing errors)
• Optimize try_mark_green and eliminate the lock on dep node colors #57065 (Optimize try_mark_green and eliminate the lock on dep node colors)
• Add a regression test for mutating a non-mut #[thread_local] #57107 (Add a regression test for mutating a non-mut #[thread_local])
• Add a target option "merge-functions", and a corresponding -Z flag (works around #57356) #57268 (Add a target option "merge-functions", and a corresponding -Z flag (works around MergeFunctions LLVM pass can generate invalid function calls under calling convention #57356))
• resolve: Add a test for issue #57539 #57551 (resolve: Add a test for issue nightly regression: ambiguous import  #57539)
• Add missing unpretty option help message #57598 (Add missing unpretty option help message)

Failed merges:

r? @ghost

[Centril]

@bors r+ p=6

[Centril]

@bors r+ p=6

[bors]

📌 Commit c5dea61 has been approved by Centril

[bors]

⌛ Testing commit c5dea61 with merge eedef01...

[bors]

💔 Test failed - checks-travis

[rust-highfive]

The job x86_64-gnu-aux of your PR failed on Travis (raw log). Through arcane magic we have determined that the following fragments from the build log may contain information about the problem.

Click to expand the log.

[01:47:28] test workspaces::ws_warn_unused ... ok
[01:47:28] 
[01:47:28] failures:
[01:47:28] 
[01:47:28] ---- doc::output_not_captured stdout ----
[01:47:28] running `/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-tools/x86_64-unknown-linux-gnu/release/cargo doc`
[01:47:28] thread 'doc::output_not_captured' panicked at '
[01:47:28]     but: expected to find:
[01:47:28] 1 | ☃
[01:47:28] 
[01:47:28] did not find in output:
[01:47:28] did not find in output:
[01:47:28]  Documenting a v0.0.1 (/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-tools/x86_64-unknown-linux-gnu/cit/t534/foo/a)
[01:47:28]     Checking a v0.0.1 (/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-tools/x86_64-unknown-linux-gnu/cit/t534/foo/a)
[01:47:28] warning: could not parse code block as Rust code
[01:47:28]  --> a/src/lib.rs:2:17
[01:47:28] 2 |               /// ```
[01:47:28]   |  _________________^
[01:47:28] 3 | |             /// ☃
[01:47:28] 4 | |             /// ```
[01:47:28] 4 | |             /// ```
[01:47:28]   | |___________________^
[01:47:28]   |
[01:47:28]   = note: error from rustc: unknown start of token: \u{2603}
[01:47:28] help: mark blocks that do not contain Rust code as text
[01:47:28] 2 |             /// ```text
[01:47:28]   |                 ^^^^^^^
[01:47:28] 
[01:47:28] 
[01:47:28]  Documenting foo v0.0.1 (/checkout/obj/build/x86_64-unknown-linux-gnu/stage2-tools/x86_64-unknown-linux-gnu/cit/t534/foo)
[01:47:28] ', src/tools/cargo/tests/testsuite/support/mod.rs:773:13
[01:47:28] note: Run with `RUST_BACKTRACE=1` environment variable to display a backtrace.
[01:47:28] 
[01:47:28] 
---
[01:47:28] command did not execute successfully: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage0/bin/cargo" "test" "--target" "x86_64-unknown-linux-gnu" "-j" "4" "--release" "--locked" "--color" "always" "--manifest-path" "/checkout/src/tools/cargo/Cargo.toml" "--features" "rustc-workspace-hack/all-static"
[01:47:28] expected success, got: exit code: 101
[01:47:28] 
[01:47:28] 
[01:47:28] failed to run: /checkout/obj/build/bootstrap/debug/bootstrap test src/test/pretty src/test/run-pass/pretty src/test/run-fail/pretty src/test/run-pass-valgrind/pretty src/test/run-pass-fulldeps/pretty src/test/run-fail-fulldeps/pretty src/tools/cargo src/tools/cargotest
[01:47:28] Build completed unsuccessfully in 0:30:51
[01:47:28] make: *** [check-aux] Error 1
[01:47:28] Makefile:50: recipe for target 'check-aux' failed
The command "stamp sh -x -c "$RUN_SCRIPT"" exited with 2.
travis_time:start:03cce2ac
$ date && (curl -fs --head https://google.com | grep ^Date: | sed 's/Date: //g' || true)
Wed Jan 16 19:33:56 UTC 2019
---
travis_time:end:1b2a0085:start=1547667239580808238,finish=1547667239604495682,duration=23687444
travis_fold:end:after_failure.3
travis_fold:start:after_failure.4
travis_time:start:196179fc
$ ln -s . checkout && for CORE in obj/cores/core.*; do EXE=$(echo $CORE | sed 's|obj/cores/core\.[0-9]*\.!checkout!\(.*\)|\1|;y|!|/|'); if [ -f "$EXE" ]; then printf travis_fold":start:crashlog\n\033[31;1m%s\033[0m\n" "$CORE"; gdb --batch -q -c "$CORE" "$EXE" -iex 'set auto-load off' -iex 'dir src/' -iex 'set sysroot .' -ex bt -ex q; echo travis_fold":"end:crashlog; fi; done || true
travis_fold:start:crashlog
obj/cores/core.3537.!checkout!obj!build!x86_64-unknown-linux-gnu!stage2!bin!rustc
[New LWP 3538]
[New LWP 3537]
warning: Could not load shared library symbols for 8 libraries, e.g. /lib/x86_64-linux-gnu/libc.so.6.
Use the "info sharedlibrary" command to see the complete listing.
Do you need "set solib-search-path" or "set sysroot"?
Core was generated by `rustc --crate-name foo src/lib.rs --color never --crate-type lib --emit=dep-inf'.
Program terminated with signal SIGABRT, Aborted.
#0  0x00007f1119274428 in ?? ()
[Current thread is 1 (LWP 3538)]
#0  0x00007f1119274428 in ?? ()
#1  0x00007f111927602a in ?? ()
#2  0x0000000000000020 in ?? ()
#3  0x0000000000000000 in ?? ()
travis_time:end:196179fc:start=1547667239608790772,finish=1547667241468957405,duration=1860166633
travis_fold:end:after_failure.4
travis_fold:start:after_failure.5
travis_time:start:2d4123cc
travis_time:start:2d4123cc
$ cat ./obj/build/x86_64-unknown-linux-gnu/native/asan/build/lib/asan/clang_rt.asan-dynamic-i386.vers || true
cat: ./obj/build/x86_64-unknown-linux-gnu/native/asan/build/lib/asan/clang_rt.asan-dynamic-i386.vers: No such file or directory
travis_fold:end:after_failure.5
travis_fold:start:after_failure.6
travis_time:start:2487925e
$ dmesg | grep -i kill

I'm a bot! I can only do what humans tell me to, so if this was not helpful or you have suggestions for improvements, please ping or otherwise contact @TimNN. (Feature Requests)