[Issue 22439] OpenBSD: Sync mman.d

[d-bugmail at puremagic.com]

https://issues.dlang.org/show_bug.cgi?id=22439

--- Comment #3 from Dlang Bot <dlang-bot at dlang.rocks> ---
dlang/druntime pull request #3615 "Merge `stable` in `mater`" was merged into
master:

- 056db3f2b1ff544bdbaf9ed1e9e5220e29ffb30c by Brian Callahan:
  Fix Issue 22439 - OpenBSD: Sync mman.d

https://github.com/dlang/druntime/pull/3615

--