[Issue 23456] New: OpenBSD: Add waitid support

[d-bugmail at puremagic.com]

https://issues.dlang.org/show_bug.cgi?id=23456

          Issue ID: 23456
           Summary: OpenBSD: Add waitid support
           Product: D
           Version: D2
          Hardware: All
                OS: Other
            Status: NEW
          Severity: enhancement
          Priority: P1
         Component: druntime
          Assignee: nobody at puremagic.com
          Reporter: bcallah at openbsd.org

OpenBSD supports waitid now. Let's add support for it.

--