[flang][OpenMP] `NO WAIT` is also a `NOWAIT`

[pawosm-arm]

In some of the important HPC projects like https://github.com/OpenRadioss/OpenRadioss some of the OpenMP directives use different spelling of NOWAIT, see:

https://github.com/OpenRadioss/OpenRadioss/blob/d271d5b5f3e5f74a4fd8153f817c6a063a0e8d0e/engine/source/assembly/depla.F#L91

...and many other places across the entire project. Flang cannot compile this until all the occurrences are replaced with NOWAIT, other compilers don't complain (testing it in fortran.godbolt.org does not confirm that claim!). It is important that Flang is being able to compile large HPC projects like this one out of the box.

[pawosm-arm]

Seems putting space in NOWAIT is not OpenMP standard. ifx, gfortran and nvfortran do not accept that either. Closing it.