[clang] [clang-tools-extra] [llvm] [clang]: reflection operator parsing for global namespace and primitive types (PR #164692)

[Erich Keane via llvm-commits]

erichkeane wrote:

Discussing offline-An experimental reflection flag is the best way forward for now.  At least until we're out of 'experimental'.

Another thing I was thinking: we should limit where we check it to JUST the places in parsing where we identify the operators.  Else, we risk hiding bugs.

1 last thing: we should diagnose in non-reflection mode the token `^` followed by `^`.  That way we can identify what that could break sooner for users.

https://github.com/llvm/llvm-project/pull/164692