x86: Avoid stack realignment when copying data with SSE register

x86: Avoid stack realignment when copying data with SSE register

To avoid stack realignment, call ix86_gen_scratch_sse_rtx to get a
scratch SSE register to copy data with with SSE register from one
memory location to another.

gcc/

	PR target/101772
	* config/i386/i386-expand.c (ix86_expand_vector_move): Call
	ix86_gen_scratch_sse_rtx to get a scratch SSE register to copy
	data with SSE register from one memory location to another.

gcc/testsuite/

	PR target/101772
	* gcc.target/i386/eh_return-2.c: New test.