[GtkGLExt] out of tree build fails

[Marcel Wysocki <maci satgnu net>]

Hello,

im trying to package gtkglext for mingw32/64 on fedora.
https://bugzilla.redhat.com/show_bug.cgi?id=894834 this is the BZ entry.

i have a problem building the package.
the .def files dont get copied over like the .pc files during the 
configure phase.
which in turn results on make failing when doing out of source tree builds.
is there any patch around?

regards

Marcel