-fno-strict-aliasing

Hi everyone.
i'm pretty new to bsd, but i have some background in linux development
and for what i have seen until now, i must say that -CURRENT is rather impressive, congrats !

I was rebuilding my base sys and noticed that any compiler flag 
that implies -fstrict-aliasing (like -O2) would break some few things,
adding "-fno-strict-aliasing" to "CFLAGS+=" in these makefiles
solves the problem for now.

usr.sbin/kldxref/Makefile
lib/libc/Makefile
lib/libpam/Makefile
libexec/ypxfr/Makefile
usr.sbin/rpc.yppasswd/Makefile