GCC 4.2 only ports

[awarecons]

It looks strange that some ports are incompatible with, for e.g. GCC
4.6.3, but in one's Makefile it's not set USE_GCC=4.2+ directly.

Some of them (more could be discovered, for e.g., via portmaster
x11/gnome2|kde4 and USE_GCC=4.6+ in /etc/make.conf):

audio/oss
devel/libgii
graphics/opencv-core
net-im/libpurple
multimedia/dirac
security/pam_helper
www/evolution-webcal
www/havp