[gfortran] Disable linear-5.f90

[NimishMishra]

With the merge of llvm/llvm-project#139386, certain aspects of linear clause processing have been enabled that can only be reliably checked with OpenMP version 5.2. However, current LLVM Flang version < 5.2, and thus incorrectly compiles code it should not. Hence, disable the test unless the OpenMP version in LLVM Flang becomes 5.2

[tarunprabhu]

Thanks for adding the comment while disabling the test.

Does flang support explicitly setting -fopenmp-version=5.2?

There is a way to override some DejaGNU annotations used in these tests, but I don't think it currently supports adding/replacing options. But if flang works correctly when setting -fopenmp-version=5.2, I could implement such an override in which case we could re-enable this test without having to wait until flang's default becomes >=5.2.

[NimishMishra]

But if flang works correctly when setting -fopenmp-version=5.2, I could implement such an override in which case we could re-enable this test without having to wait until flang's default becomes >=5.2.

Thanks. Yes, flang supports specifying a specific OpenMP version through the -fopenmp-version option.