Tracking issue for OpenMP 5.0 support

Nobody has claimed this yet.

In https://github.com/llvm/llvm-project/issues/63633, I had asked:
> is there an issue somewhere that's tracking the finalization of OpenMP 5.0 support?

Since this hasn't gotten any response in 6+ months, I'm opening an issue now. This is intentionally on a low footprint; other approaches are possible (e.g. libcxx uses individual issues for conformance with C++ features and issues, all of which are tracked in one [project](https://github.com/orgs/llvm/projects/31)).

Going by the points for 5.0 in https://clang.llvm.org/docs/OpenMPSupport.html that aren't marked done yet:

* [ ] `#pragma omp loop (directive)`, last updated: https://github.com/llvm/llvm-project/commit/b41bf9d8576f44e30726e42d31f760032c08333d (July 2023)
https://github.com/llvm/llvm-project/blob/8b18aa0b1ec2de76d47748a4d13c4de02b4d8580/clang/docs/OpenMPSupport.md#L86

* [ ] `#pragma omp loop bind`, last updated: https://github.com/llvm/llvm-project/commit/b41bf9d8576f44e30726e42d31f760032c08333d (July 2023)
https://github.com/llvm/llvm-project/blob/8b18aa0b1ec2de76d47748a4d13c4de02b4d8580/clang/docs/OpenMPSupport.md#L87

* [ ] `task affinity`, last update: https://github.com/llvm/llvm-project/commit/608338cca579900a85f60a501adf6fa3789999c5 (Sept. 2021); the referenced [repo](https://github.com/jklinkenberg/openmp/tree/task-affinity) dates back to before the monorepo and hasn't been updated in 7 years
https://github.com/llvm/llvm-project/blob/8b18aa0b1ec2de76d47748a4d13c4de02b4d8580/clang/docs/OpenMPSupport.md#L99

* [ ] `infer target functions from initializers`, last updated: https://github.com/llvm/llvm-project/commit/40fe351cf699eda8d7d9a72c7bbbb37cef7f3164 (Sept. 2019)
https://github.com/llvm/llvm-project/blob/8b18aa0b1ec2de76d47748a4d13c4de02b4d8580/clang/docs/OpenMPSupport.md#L110

* [ ] `clause: in_reduction`, last updated: https://github.com/llvm/llvm-project/commit/bcf754a3212c12ecc896bac66c599d571eca57d9 (Nov. 2019)
https://github.com/llvm/llvm-project/blob/8b18aa0b1ec2de76d47748a4d13c4de02b4d8580/clang/docs/OpenMPSupport.md#L118

* [ ] `structure mapping of references`: unclaimed
https://github.com/llvm/llvm-project/blob/8b18aa0b1ec2de76d47748a4d13c4de02b4d8580/clang/docs/OpenMPSupport.md#L120

* [ ] `clause: unified_address`, last updated: https://github.com/llvm/llvm-project/commit/ac430336318a1abe6e4726e8df49ee0e6b779691 (Feb. 2020)
https://github.com/llvm/llvm-project/blob/8b18aa0b1ec2de76d47748a4d13c4de02b4d8580/clang/docs/OpenMPSupport.md#L126

* [ ] `clause: reverse_offload`, last updated: https://github.com/llvm/llvm-project/commit/a37d7472225442227c531ce85a7448499f70b72e (July 2023)
https://github.com/llvm/llvm-project/blob/8b18aa0b1ec2de76d47748a4d13c4de02b4d8580/clang/docs/OpenMPSupport.md#L127

* [ ] `clause: dynamic_allocators`: last updated: https://github.com/llvm/llvm-project/commit/40fe351cf699eda8d7d9a72c7bbbb37cef7f3164 (Sept. 2019)
https://github.com/llvm/llvm-project/blob/8b18aa0b1ec2de76d47748a4d13c4de02b4d8580/clang/docs/OpenMPSupport.md#L129

* [ ] `pointer attachment`: last updated: https://github.com/llvm/llvm-project/commit/04a123b17c1ab097e3475da53a7e485c7b184a04 (Aug. 2026)
https://github.com/llvm/llvm-project/blob/ecd6a18e03d37c2bcaf9893d9ae2698b66ac2e83/clang/docs/OpenMPSupport.md#L137

* [ ] `metadirectives`, last update: https://github.com/llvm/llvm-project/commit/35e743d4bf1960a9ea982227a6159325784c56b9 (May 2025)
https://github.com/llvm/llvm-project/blob/8b18aa0b1ec2de76d47748a4d13c4de02b4d8580/clang/docs/OpenMPSupport.md#L144

Start with clang/docs/OpenMPSupport.md and the linked issue 63633; review the unchecked OpenMP 5.0 items and their referenced commits or repositories. This is a tracking issue rather than a self-contained change, and done means the listed items are implemented or their status is updated.

Written by the indexing model from the issue text.