tree c1285bd06cff99fce774ba74ad531ce3d5065f15
parent fe913c11dcbad2a65ac4626cf7d943af1642e742
author Eric Cousineau <eric.cousineau@tri.global> 1491806648 +0000
committer Jakob Buchgraber <buchgr@google.com> 1491817724 +0200

Provide more information regarding compiler

This addresses #2761, to provide a minor improvement if neither `gcc` or `CC` are found on the path.
Let me know if you would like anything changed!

Local qualification steps:
```
$ cd bazel
$ git rebase 0.4.5   # Did not want to spend too much time synchronizing derived stuff in master
$ ln -s ~/Downloads/bazel-0.4.5-dist/derived .
$ ./compile.sh
$ export PATH=~+/output/bazel;$PATH
$ cd .../someproject
$ CC=clang-9000 bazel build //package:test
Cannot find gcc or CC (clang-9000), either correct your path or set the CC environment variable.
```

Closes #2773.
PiperOrigin-RevId: 152658002