Don't require --unstable for Deno.getUid() and Deno.getGid()

[martin-braun]

Deno.getUid() and Deno.getGid() should just return null on Windows systems, but not require the --unstable keyword, so they can be used in deno_std for permission checks that are only necessary on POSIX systems.

This issue blocks #2785

Context:

Windows will raise a Deno.errors.PermissionDenied when calling Deno.stat on a directory/file that the user cannot read. However, on POSIX systems Deno.stat will success nonetheless. To avoid opening the file when trying to verify permissions, one could compare Deno.getUid() and Deno.getGid() to FileInfo.uid and FileInfo.gid to validate ownership of a given directory/file to further validate permissions by parsing FileInfo.mode accordantly.

FileInfo.mode returns null and Deno.chmod is not working on Windows, but those APIs requires no --unstable flag. So should Deno.getUid() and Deno.getGid() in my opinion.

[iuioiua]

I believe this is an issue for the main repo and not deno_std.

[cjihrig]

FYI - denoland/deno#16424 (the APIs were renamed to uid() and gid() in the last release)