* gcc.c (set_multilib_dir): Don't access *end.

	Use memcpy instead of strncpy.  Don't write beyond malloced buffer.
	(print_multilib_info): Don't show paths starting with ".:".
	* genmultilib: Add new option, "yes" if multilibs are enabled.
	Update comments.  If multilibs not enabled, print .:${osdirout}
	for each directory.  If multilibs are enabled, always print
	${dirout}:${osdirout}, even if the two are the same.
	* Makefile.in (s-mlib): Pass @enable_multilib@ to genmultilib.
	Pass all MULTILIB_* variables to genmultilib even if
	--disable-multilib but MULTILIB_OSDIRNAMES is not empty.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@57846 138bc75d-0d04-0410-961f-82ee72b054a4