[clang] [Driver] Add support for GCC installation detection in Baremetal toolchain (PR #121829)

[Daniel Thornburgh via cfe-commits]

mysterymath wrote:

> Do the fuchsia builders actually produce output on a failure? We seem to just get exit code 1, but no indication of what filecheck had problems with.

They do; here's a link! Let me know if you have an problems with the Web UI; I can paste things here if so.
https://luci-milo.appspot.com/ui/p/fuchsia/builders/toolchain.ci/clang-linux-x64/b8711783358287375697/overview

https://github.com/llvm/llvm-project/pull/121829