Merge 7e31b45d6a2571ff17426930dcbb784473a965b4 into 17.0.X

[brad0]

[OpenMP] Use the more appropriate function to retrieve the thread id on OpenBSD (#65553)

Use the getthrid() function instead of a syscall.

[brad0]

/cherry-pick 7e31b45

[llvmbot]

@llvm/issue-subscribers-openmp

Author: Brad Smith (brad0)

[OpenMP] Use the more appropriate function to retrieve the thread id on OpenBSD (#65553)

Use the getthrid() function instead of a syscall.

[llvmbot]

/branch llvm/llvm-project-release-prs/issue69545

[llvmbot]

/pull-request llvm/llvm-project-release-prs#741