[clang] [llvm] [openmp] [offload][OpenMP] Re-enable strict modifier for num_threads (PR #163565)

[Shilei Tian via cfe-commits]

shiltian wrote:

IMHO if we want to add this back, we will need to fix OpenMPOpt first or along side such that we'd not introduce these many wrappers.

https://github.com/llvm/llvm-project/pull/163565