* irix-core.c: New file for Irix 4 and Irix 5 core support.

	* irix-core.c: New file for Irix 4 and Irix 5 core support.
	Functions taken out of coff-mips.c.  Handle vmap type VMAPFILE.
	* coff-mips.c: Irix 4 core file support moved to irix-core.c.
	* targets.c: If IRIX_CORE defined, include irix_core_vec in
	target_vector.
	* config/irix4.mh (HDEFINES): Add -DIRIX_CORE.
	(HDEPFILES): Define to be irix-core.o.
	* config/irix5.mh (HDEFINES): Define to be -DIRIX_CORE.
	(HDEPFILES): Define to be irix-core.o.
	* Makefile.in (OPTIONAL_BACKENDS): Added irix-core.o.  Removed
	sco-core.o, which no longer exists.
	(CFILES): Added all *-core.c files.
	Rebuilt dependencies.