This adds the necessary guards and includes for the Android modules.
While the module does not compile currently due to nullability
differences (and in some cases missing declarations), this at least
brings the module to a point where we can start working on the errors
and differences to create a maintainable codebase for Android.
We need to use `FILE_FLAG_BACKUP_SEMANTICS` to ensure that we are able
to diff directories as well. Previously we would mishandle this case and
was caught by the test suite.
Thanks to Jeremy Day for helping resolve this!
* FoundationEssentials: repair the Windows build after tweaks
The changes to repair the macOS/Linux build adversely impacted the
Windows build. Accommodate the API and logic changes for Windows.
* FoundationEssentials: implement file diffing support for Windows
Windows does not have the same Unix file system APIs (e.g. FTS).
Implement a platform specific implementation to compare files on
Windows.
When trying to revive the Windows port, these warnings clutter the
current set of things to resolve still. Silence the warnings by
explicitly ignoring the results.
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.
