On non-Windows targets we ensure that the path exists when we attempt to
query the attributes of the path. This adds the same check on Windows so
that we can have similar behaviour on all platforms.
Follow the expected behaviour to drop invalid modification dates, e.g.
`+NaN`. This matches the semantics that are expected on Unix and avoids
a crash due to the initialiser.
This allows for us to use the constants without explicitly casting the
type to `DWORD` on each site of use. By providing the shadowing
overload we can simply use the constants without impacting the
readability of the surrounding code.
Add a helper for time conversion and remove some functions which do not
make sense on Windows - users are not identified by integral IDs but
rather by SIDs. This helps reduce the error diagnostics when building
FoundationEssentials on Windows.
This allows us to get further into building FoundationEssentials once
again on Windows. Much of the file system work has resulted in this
module no longer being viable on Windows and will need to be replaced to
allow building on Windows which does not have the `fts` APIs.
