[clang] nonblocking/nonallocating attributes (was: nolock/noalloc) (PR #84983)

[Doug Wyatt via cfe-commits]

dougsonos wrote:

> @dougsonos Just merged a pr that diagnoses unexpanded parameter packs when an attribute is parsed, so could you double-check if that call to `DiagnoseUnexpandedParameterPack` is still necessary?

I just re-merged main to the branch and verified that the call to `DiagnoseUnexpandedParameterPack` is no longer needed.

https://github.com/llvm/llvm-project/pull/84983