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

[Aaron Ballman via cfe-commits]

https://github.com/AaronBallman commented:

> @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)

Sorry, there was a US holiday on Monday and I was mostly out on Friday, so that's why there was a delay in review. In the future, I would recommend waiting before landing significant changes like these unless the review is accepted by a maintainer or someone known to be familiar with that area of the code. That reduces pressure on reviewers and allows folks to be sick/take vacations/etc without things landing out from under them. As it turns out, I can no longer leave suggested changes on the PR because it was already merged (thanks, GitHub....), so my review comments will be somewhat awkward.

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