[clang] [llvm] [PowerPC] Support -mno-red-zone option (PR #94581)

[Chen Zheng via cfe-commits]

https://github.com/chenzheng1030 approved this pull request.

The small LIT cases seem all good. Based on that, the patch LGTM.

If possible, can you run some big applications with `-mno-redzone` to double confirm the functionality? I am not so sure about its quality since the option seems not be tested on PPC at all...

https://github.com/llvm/llvm-project/pull/94581