USE of PORTNAME_* should be discouraged wherever possible. The code

*should* be intelligent enough that:

#if defined(__FreeBSD__) works, where __FreeBSD__ is actually defined
by the compiler itself.

Makefile.global used to have -DPORTNAME_<port> -D<port> as part of the flags
for gcc while all occurances of PORTNAME_<port> slowly get removed from
the source tree...