gas/

gas/
	* config/tc-mips.h (mips_nop_opcode): Declare.
	(NOP_OPCODE): Define.
	(mips_segment_info): New structure.
	(TC_SEGMENT_INFO_TYPE): Use it instead of insn_label_list.
	* config/tc-mips.c (label_list): Adjust for new TC_SEGMENT_INFO_TYPE.
	(mips_record_mips16_mode): New function.
	(install_insn): Call it.
	(mips_align): Likewise.  Turn the fill argument into an "int *".
	Use frag_align_code for code segments if no fill data is given.
	(s_align): Adjust call accordingly.
	(mips_nop_opcode): New function.
	(mips_handle_align): Use the first variable byte to decide which
	nop sequence is needed.  Use md_number_to_chars and mips16_nop_insn.

gas/testsuite/
	* gas/mips/align2.s, gas/mips/align2.d, gas/mips/align2-el.d: New
	tests.
	* gas/mips/mips.exp: Run them.