When having a TARGET value that contains whitespace, linking would fail
with MinGW. This was, because the function createResponseFile stitched
together a file name like this:
objectScript."Target Name".Release
The inner double quotes make the file name invalid.
Fix this by retrieving QMAKE_ORIG_TARGET with the var() method instead
of fileVar(). The latter quotes the return value if it contains
spaces.
Pick-to: 5.15 6.2 6.3
Fixes: QTBUG-99522
Change-Id: Ieb7dcf3fbbd8a75de5a9b9a6beadb2170dddf35d
Reviewed-by: Kai Koehne <kai.koehne@qt.io>