[clang] [llvm] [Clang] [OpenMP] Support NOWAIT with optional argument (PR #128742)

[Michael Klemm via llvm-commits]

mjklemm wrote:

> Should the `nowait(EXPR)` behavior be guarded by the OpenMP version flag? It seems to me that the tests would currently not respect which OpenMP version is selected and always generate the error.

I agree.  This should be under `-fopenmp-version=6.0`

https://github.com/llvm/llvm-project/pull/128742