CoreFoundation: implement mapping from file descriptor to binary
CoreFoundation: implement mapping from file descriptor to binary

This avoids an annoying warning in the Windows path that was introduced
with the last update to Foundation.  This implements the functionality
on Windows as well.

apple/swift-corelibs-foundation,apple/swift-corelibs-foundation,apple/swift-corelibs-foundation,apple/swift-corelibs-foundation,apple/swift-corelibs-foundation