[clang] [NFC][clang][driver] Improve readability of long and complex if statement (PR #164994)

[Manuel Carrasco via cfe-commits]

mgcarrasco wrote:

> I like this in concept, but a few of these take it a bit too far in the other direction, stuff like `IsAMDGPUOrHIP` isn't much more readable than `IsAMDGPU || IsHIP`. Try to simplify this a bit more and possible pull in some conditions from the previous and later lines

Thanks @jhuber6. I've updated the PR.

https://github.com/llvm/llvm-project/pull/164994