[clang] Add 'enum_select' diagnostic selection to clang. (PR #122505)

[Aaron Ballman via cfe-commits]

https://github.com/AaronBallman commented:

Thank you for working on this! We should probably also update https://clang.llvm.org/docs/InternalsManual.html#formatting-a-diagnostic-argument so that folks know how to use this properly and we advertise it more broadly.

https://github.com/llvm/llvm-project/pull/122505