[OpenMP] Implement 5.0 memory management
- Replace HBWMALLOC API with more general MEMKIND API, new functions and variables added.
- Have libmemkind.so loaded when accessible.
- Redirect memspaces to default one except for high bandwidth which is processed separately.
- Ignore some allocator traits e.g., sync_hint, access, pinned, while others are processed normally e.g., alignment, pool_size, fallback, fb_data, partition.
- Add tests for memory management
Patch by Andrey Churbanov
Differential Revision: https://reviews.llvm.org/D59783