so we can remove unnecessary calls to the OUString(literal) constructor
when calling constructors like this:
   Foo(OUString("xxx"), 1)

Change-Id: I1de60ef561437c86b27dc9cb095a5deb2e103b36
Reviewed-on: https://gerrit.libreoffice.org/33698Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>