mips.md (SHORT): New mode macro.

mips.md (SHORT): New mode macro.

	* config/mips/mips.md (SHORT): New mode macro.
	(size): New mode attribute.
	(extend[qh]i[sd]i2): Redefine using :GPR and :SHORT.
	(*extend[qh]i[sd]i2): New define_insn_and_split, combining previous
	*extend[qh]i[sd]i2 and *extend[qh]i[sd]i2_mem patterns.  Use only if
	!ISA_HAS_SEB_SEH.
	(*extend[qh]i[sd]i2_se[bh]): New pattern, combining previous
	*extend[qh]isi2_hw patterns and extending them to di.
	(extendqihi2): Implement as define_insn_and_split that produces
	extendqisi2 after reload.

From-SVN: r87075