* config/tc-mips.c (mips_4650): New static variable.

	* config/tc-mips.c (mips_4650): New static variable.
	(md_begin): Handle a cpu string of "4650".  If mips_4650 was not
	initialized, set it to 0.
	(append_insn): Don't insert nops around HI and LO on a 4650.
	(mips_emit_delays): Likewise.
	(mips_ip): Use INSN_ISA mask to check ISA of instruction.  Check
	for INSN_4650.
	(md_longopts): Add m4650 and no-m4650.
	(md_parse_option): Handle mips-cpu=4650.  Handle -m4650 and
	-no-m4650.
	* doc/as.texinfo: Document new MIPS options.