[clang] [clang][AMDGPU] Clean-up handling of named barrier type (PR #207687)

[Yaxun Liu via cfe-commits]

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

LGTM. The latest changes address my comments, including the AMD SPIR-V diagnostic and wrapper coverage.

https://github.com/llvm/llvm-project/pull/207687