Fix 64-bit *intmax_t definitions on IRIX

Fix 64-bit *intmax_t definitions on IRIX

	* config/mips/iris6.h [!USED_FOR_TARGET] (long_intmax): Declare.
	(INTMAX_TYPE): Use it.
	(UINTMAX_TYPE): Likewise.
	(SUBTARGET_OVERRIDE_OPTIONS): Define.
	(irix6_c_common_override_options): Declare.
	(C_COMMON_OVERRIDE_OPTIONS): Define.
	* config/mips/mips.c [TARGET_IRIX6] (long_intmax): Define.
	* config/mips/irix6-c.c: New file.
	* config/mips/t-irix6 (irix6-c.o): New target.
	* config.gcc (mips-sgi-irix6.5): Set c_target_objs,
	cxx_target_objs.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/branches/gcc-4_7-branch@184921 138bc75d-0d04-0410-961f-82ee72b054a4