tests.cc-wrapper: verify building with sanitizers

pkgs/build-support/cc-wrapper/default.nix

···
 , stdenvNoCC, nativeTools, propagateDoc ? !nativeTools, noLibc ? false, nativeLibc, nativePrefix ? ""
 , cc ? null, libc ? null, bintools, coreutils ? null, shell ? stdenvNoCC.shell
 , extraPackages ? [], extraBuildCommands ? ""
-, isGNU ? false, isClang ? cc.isClang or false, gnugrep ? null
+, isGNU ? false, isClang ? cc.isClang or false, isCompilerRT ? false, gnugrep ? null
 , buildPackages ? {}
 }:
 
···
     # Binutils, and Apple's "cctools"; "bintools" as an attempt to find an
     # unused middle-ground name that evokes both.
     inherit bintools;
-    inherit libc nativeTools nativeLibc nativePrefix isGNU isClang default_cxx_stdlib_compile;
+    inherit libc nativeTools nativeLibc nativePrefix isGNU isClang isCompilerRT default_cxx_stdlib_compile;
 
     emacsBufferSetup = pkgs: ''
       ; We should handle propagation here too

pkgs/development/compilers/llvm/6/default.nix

···
         targetLlvmLibraries.libcxxabi
         targetLlvmLibraries.compiler-rt
       ];
+      isCompilerRT = true;
       extraBuildCommands = ''
         rsrc="$out/resource-root"
         mkdir "$rsrc"

pkgs/test/cc-wrapper/default.nix

···
 
     NIX_LDFLAGS="-L$NIX_BUILD_TOP/foo/lib -rpath $NIX_BUILD_TOP/foo/lib" $CC -lfoo -o ldflags-check ${./ldflags-main.c}
     ./ldflags-check
+  '' + stdenv.lib.optionalString (stdenv.cc.isCompilerRT or false) ''
+
+    $CC -o sanitizers -fsanitize=address,undefined ${./sanitizers.c}
+    ./sanitizers
+  '' + ''
 
     touch $out
   '';

pkgs/test/cc-wrapper/sanitizers.c

···
+#include <sanitizer/asan_interface.h>
+#include <stdio.h>
+
+int main(int argc, char **argv)
+{
+  fprintf(stderr, "ok\n");
+  return 0;
+}