[clang] default clause replaced by otherwise clause for metadirective in OpenMP 5.2 (PR #125648)

[Urvi Rav via cfe-commits]

ravurvi20 wrote:

> Did anybody run the OpenMP VV suite before and after this change? Curious to know if that improves results.

The changes I implemented are related to parsing, specifically addressing the deprecation of the default clause. These modifications do not impact the results, as they primarily refine how parsing is handled. Previously, keywords such as default, otherwise, or other variations were all parsed without distinction. With my changes, the parsing behavior now aligns with the expected standard—supporting default for OpenMP versions lower than 5.2 and otherwise for higher versions. Additionally, a warning is now generated when default is used in higher versions.

I also validated these changes by running the OpenMP VV suite to ensure correctness.

https://github.com/llvm/llvm-project/pull/125648