We could make these changes on the Geany side, I put it here explicitly to ensure we use the same compiler variant for Geany *and* G-P.
Alternatively, we could end up in compiling Geany with the -posix variant and G-P with the -win32 variant which may work or may not. Or we had to duplicate the changes in the G-P build script as well.
But as the G-P binaries loaded directly into Geany, I think we should ensure they are build the same way, at least as far as we can.