ProFileEvaluator::absoluteFileValues() now returns only files, which
allows us to skip the subsequent QFileInfo::isFile() calls at some
call sites.

as a side effect, IoUtils::fileType() does not see anything except
regular files and directories any more. that's not expected to be a
problem, given the function's scope.

Change-Id: I53063ad8cacb3afe5cc1baf6d6d5feba3465e74f
Reviewed-by: Tobias Hunger <tobias.hunger@qt.io>