[Openmp-commits] [openmp] Add openmp support to System z (PR #66081)

[Ilya Leoshkevich via Openmp-commits]

iii-i wrote:

- The `createAtomicExpandPass()` change was merged separately (https://github.com/llvm/llvm-project/pull/70398).

- The `kmp_depend_info` change was merged separately (https://github.com/llvm/llvm-project/pull/69995).

- The `__kmp_invoke_microtask()` and `print_possible_return_addresses()` changes correspond to https://github.com/llvm/llvm-project/commit/d415431bb74bb0ad5e732a2a6cc3508991cf5743 and https://github.com/llvm/llvm-project/commit/91dead15d919ea9dfab52b2b4b46ef49c4817eb5 respectively; I would squash both into this PR.

What's missing are:

- https://github.com/llvm/llvm-project/commit/6eadf47e6a1fde25647ae46aed7c3f9be6afd16e (Build openmp tests with -mbackchain)

- https://github.com/llvm/llvm-project/commit/a3d85592f651a7172871408bd9aafe29dc1635b9 (Compile __kmp_invoke_task with -mbackchain)

- https://github.com/llvm/llvm-project/commit/13bea32d8cfc85887cc7637635252a2d8cfe9fc0 (Implement s390x /proc/cpuinfo parsing)

https://github.com/llvm/llvm-project/pull/66081