[clang] [OpenMP] Change default version to OMP6.0. (PR #122108)

[Saiyedul Islam via cfe-commits]

https://github.com/saiislam requested changes to this pull request.

I agree with both points raised by @mjklemm .

Even when we make 6.0 as default, I am pretty sure that many more LIT tests need to be updated. Please see https://reviews.llvm.org/D129635 for last update exercise.

We also will have to ensure that testing coverage for 5.1 is not reduced by making 6.0 as default, which might require modifying some/many test cases manually.

What to do with 4.5 test coverage is another question we need to discuss.

https://github.com/llvm/llvm-project/pull/122108