[clang] [llvm] [Clang][OpenMP] Support expression semantics in target update fields with non-contiguous array sections (PR #176708)

[Amit Tiwari via cfe-commits]

amitamd7 wrote:

> The PR still makes functional changes in clang's codegen files, which would impact the output IR generated by clang, so it should be accompanied with corresponding CG tests, as discussed [here](https://github.com/llvm/llvm-project/pull/176708#discussion_r2710403575).
> 
> The change in the runtime behavior is rightly covered via "offload/test" tests, but we still need to cover clang CG changes with their own LIT tests.
> 
> Also, for branches with open PRs, it's preferable to use `git fetch upstream main && git merge upstream/main && git push` instead of `git pull --rebase upstream main && git push --force`, to avoid clobbering previous review history from the PR.

Added a test for the same. I'll keep the git-related advice in mind. Thanks.

https://github.com/llvm/llvm-project/pull/176708