OpenGL inside of Qt applications. It is a Good Thing (tm) to take care
of that in this port instead of patching Makefiles in other ports that
make use of tmake.
Currently there seem to be no ports that make use of tmake and don't
depend on OpenGL. But they should not be affected anyway as the qtgl
library does contain all symbols from the qt lib.
PR: 26495
Submitted by: maintainer
