[clang] [clang][cmake] Apply bolt optimizations as part of the clang target (PR #119896)

[Amir Ayupov via cfe-commits]

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

Thank you, looks good overall. When you land, please monitor clang-bolt builder which exercises this logic.

https://github.com/llvm/llvm-project/pull/119896