[clang] [clang-tools-extra] [Clang] [C2y] Implement N3355 ‘NamedLoops’ (PR #152870)

[Erich Keane via cfe-commits]

https://github.com/erichkeane commented:

Sorry, this fell off my list of reviews somehow!  Anyway, the overall direction is WAY better than last time I was able to take a look, I think this is pretty close. 

Thanks!

https://github.com/llvm/llvm-project/pull/152870