Allow MMX intrinsic emulation with SSE/SSE2/SSSE3.  Don't enable MMX ISA
by default with TARGET_MMX_WITH_SSE.

For pr82483-1.c and pr82483-2.c, "-mssse3 -mno-mmx" compiles in 64-bit
mode since MMX intrinsics can be emulated wit SSE.

gcc/

	PR target/89021
	* config/i386/i386-builtin.def: Enable MMX intrinsics with
	SSE/SSE2/SSSE3.
	* config/i386/i386-builtins.c (ix86_init_mmx_sse_builtins):
	Likewise.
	* config/i386/i386-expand.c (ix86_expand_builtin): Allow
	SSE/SSE2/SSSE3 to emulate MMX intrinsics with TARGET_MMX_WITH_SSE.
	* config/i386/mmintrin.h: Only require SSE2 if __MMX_WITH_SSE__
	is defined.

gcc/testsuite/

	PR target/89021
	* gcc.target/i386/pr82483-1.c: Error only on ia32.
	* gcc.target/i386/pr82483-2.c: Likewise.

From-SVN: r271252