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

[Corentin Jabot via cfe-commits]

cor3ntin wrote:

Thanks for working on that; I will review later.

I have some concerns about exposing that more widely than in C2y for _now_
We are quite early in the C2y cycle, there have been proposals altering the design, and C++ has express interest in doing something maybe similar.
We should gather deployment experience before backing us, and committees in a corner.


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