Problems:
* mmap of size 0 works, add test in QFSFileEnginePrivate::map to
make sure wasm platform behaves as the other platforms
* qwe// is a valid filename on wasm, QSKIP test
* applicationFilePath does not exist on wasm.
* /dev/zero does not exist on wasm, file bug, skip test
* blocking pipes do not exist on wasm, QSKIP test
* socketpair does not exist on wasm, QSKIP test
Change-Id: I1705c543782cbcb92a7ebed2fc2792613524c686
Reviewed-by: Morten Johan Sørvig <morten.sorvig@qt.io>
c0fdd4b451