[clang] [lld] [llvm] Deprecate the `-fbasic-block-sections=labels` option. (PR #107494)

[Fangrui Song via cfe-commits]

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

(Thanks for the patch. I am on vacation and may be slow/inconvenient to respond.)

https://github.com/llvm/llvm-project/pull/107494