Update aarch64 compiler, add workaround for broken host GCC v11 (#70)

Artifacts.toml

@@ -1,13 +1,13 @@
 [["GCCBootstrap-aarch64-apple-darwin14.v11.0.0-iains.x86_64-linux-musl.squashfs"]]
 arch = "x86_64"
-git-tree-sha1 = "64c870e506f0f6e6004e784c830884fbc3fb056f"
+git-tree-sha1 = "4a3caffaeb4b219b3c7976c56619f97217e29418"
 lazy = true
 libc = "musl"
 os = "linux"
 
 [["GCCBootstrap-aarch64-apple-darwin14.v11.0.0-iains.x86_64-linux-musl.unpacked"]]
 arch = "x86_64"
-git-tree-sha1 = "c1fbed7cf7be10fe7fb973e1dc7865b973226108"
+git-tree-sha1 = "0397882e23914502eb0de6294203852eb8e917cf"
 lazy = true
 libc = "musl"
 os = "linux"
@@ -1332,20 +1332,6 @@ os = "linux"
     sha256 = "f4550645592653d21ffcaf1fc67bba734105aaa541fc0468193e358ec303ae2e"
     url = "https://github.com/JuliaPackaging/Yggdrasil/releases/download/GCCBootstrap-v9.1.0+2/GCCBootstrap-x86_64-linux-gnu.v9.1.0.x86_64-linux-musl.unpacked.tar.gz"
 
-[["GCCBootstrap-x86_64-linux-musl.v11.0.0-iains.x86_64-linux-musl.squashfs"]]
-arch = "x86_64"
-git-tree-sha1 = "9e9300a7d0cfa7aa9a26b027e43a1d4bbf3c8f6d"
-lazy = true
-libc = "musl"
-os = "linux"
-
-[["GCCBootstrap-x86_64-linux-musl.v11.0.0-iains.x86_64-linux-musl.unpacked"]]
-arch = "x86_64"
-git-tree-sha1 = "a1999c031cd6d255819cf34981f7d12af21e6e33"
-lazy = true
-libc = "musl"
-os = "linux"
-
 [["GCCBootstrap-x86_64-linux-musl.v4.8.5.x86_64-linux-musl.squashfs"]]
 arch = "x86_64"
 git-tree-sha1 = "0528dd9437b8c7b1ec25e8a1aac2fdf2f56cd3c5"

src/Rootfs.jl

@@ -370,7 +370,7 @@ const available_gcc_builds = [
     GCCBuild(v"7.1.0", (libgfortran_version = v"4", libstdcxx_version = v"3.4.23", cxxstring_abi = "cxx11")),
     GCCBuild(v"8.1.0", (libgfortran_version = v"5", libstdcxx_version = v"3.4.25", cxxstring_abi = "cxx11")),
     GCCBuild(v"9.1.0", (libgfortran_version = v"5", libstdcxx_version = v"3.4.26", cxxstring_abi = "cxx11")),
-    GCCBuild(v"11-iains", (libgfortran_version = v"5", libstdcxx_version = v"3.4.26", cxxstring_abi = "cxx11")),
+    GCCBuild(v"11.0.0-iains", (libgfortran_version = v"5", libstdcxx_version = v"3.4.28", cxxstring_abi = "cxx11")),
 ]
 const available_llvm_builds = [
     LLVMBuild(v"6.0.1"),
@@ -500,6 +500,11 @@ function choose_shards(p::AbstractPlatform;
     host_platform = Platform("x86_64", "linux"; libc="musl")
 
     function find_shard(name, version, archive_type; target = nothing)
+        # Ugly hack alert!  Because GCC 11 has somehow broken C++, we pair GCC 9 with GCC 11 on MacOS
+        if name == "GCCBootstrap" && version.major == 11 && target !== nothing && Sys.islinux(target)
+            version = v"9.1.0"
+        end
+
         for cs in all_compiler_shards()
             if cs.name == name && cs.version == version &&
                (target === nothing || platforms_match(cs.target, target)) &&
@@ -522,9 +527,12 @@ function choose_shards(p::AbstractPlatform;
                 return false
             end
         end
-        if !shard_exists("GCCBootstrap", getversion(GCC_build), archive_type; target=host_platform)
-            return false
-        end
+
+        # Ugly hack alert!  We disable this check because we don't even ship a GCC 11 build
+        # for the host platform because it's prerelease and broken.
+        #if !shard_exists("GCCBootstrap", getversion(GCC_build), archive_type; target=host_platform)
+        #    return false
+        #end
         return true
     end