[clang] [clang-tools-extra] [llvm] [clang] Introduce diagnostics suppression mappings (PR #112517)

[kadir çetinkaya via cfe-commits]

kadircet wrote:

@AaronBallman merging this to main now. PLMK if you have any concerns, I am happy to address them post-submit (or revert if need be)

https://github.com/llvm/llvm-project/pull/112517