This adjusts the API usage to account for differences on Android. The
biggest source of difference is the nullability, particularly in the
`fts` APIs. Unfortunately, `MMAP_FAILED` is not imported by the clang
importer due to the casting involved so we manually inline the constant
at the single site.
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.
When enumerating a directory on Windows, we would fail to increment the
iterator as we would increment _after_ the return. Insert a `defer`'ed
increment on the iterator to allow us to track the state properly.
Because the iteration was may have completed on the previous run, we
need to track an additional bit of state as `bValid` which provides us
an indication if iteration has completed.
Implement the directory enumeration operations in FileManager on
Windows. The implementation uses the Win32 API surface to ensure that we
can use the full features of the platform.
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.
