i386: Emulate MMX punpcklXX/punpckhXX with SSE punpcklXX

i386: Emulate MMX punpcklXX/punpckhXX with SSE punpcklXX

Emulate MMX punpcklXX/punpckhXX with SSE punpcklXX.  For MMX punpckhXX,
move bits 64:127 to bits 0:63 in SSE register.  Only SSE register source
operand is allowed.

	PR target/89021
	* config/i386/i386-expand.c (ix86_split_mmx_punpck): New function.
	* config/i386/i386-protos.h (ix86_split_mmx_punpck): New
	prototype.
	* config/i386/mmx.m (mmx_punpckhbw): Changed to
	define_insn_and_split to support SSE emulation.
	(mmx_punpcklbw): Likewise.
	(mmx_punpckhwd): Likewise.
	(mmx_punpcklwd): Likewise.
	(mmx_punpckhdq): Likewise.
	(mmx_punpckldq): Likewise.

From-SVN: r271216