Duplicate the Handle instead of the fd on Windows
Duplicate the Handle instead of the fd on Windows

Since getting an fd from a handle transfers ownership, we duplicate the
handle before getting an fd from it.

apple/swift-corelibs-foundation,e78l/swift-corelibs-foundation,apple/swift-corelibs-foundation,apple/swift-corelibs-foundation,e78l/swift-corelibs-foundation,e78l/swift-corelibs-foundation,apple/swift-corelibs-foundation,apple/swift-corelibs-foundation,e78l/swift-corelibs-foundation,e78l/swift-corelibs-foundation