[clang] [llvm] [Clang][OpenMP] Handled `NonContig` Descriptor `DimCount` (PR #181987)

[Abhinav Gaba via cfe-commits]

https://github.com/abhinavgaba commented:

I don't think the `unittests/*` files are needed. Please wait for @alexey-bataev to review again.

Also, for future reference, for cases where a test is already compiling, it's preferable to first commit the test with checks for the current IR, then in a follow-up commit, add the fix and show which lines changed in the IR. https://llvm.org/docs/TestingGuide.html#id17

https://github.com/llvm/llvm-project/pull/181987