[clang] [clang][Driver] Handle ROCm installation layout of lib/llvm/bin/clang (PR #138928)

[Yaxun Liu via cfe-commits]

https://github.com/yxsamliu approved this pull request.

Since TheRock build needs this fix, we will merge it first.

I will add a lit test for it.

https://github.com/llvm/llvm-project/pull/138928