PR rtl-optimization/89865

	PR rtl-optimization/89865
	* config/i386/i386.md
	(SWI12 peephole for mem {+,-,&,|,^}= x; mem != 0): Fix up operand
	numbers not to clash with the additional operands[4].
	(peepholes for mem {+,-,&,|,^}= x; mem != 0): New peephole2s
	with extra register copy in the middle.

	* gcc.target/i386/pr49095.c: Adjust number of expected RMW spots
	on ia32.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@270205 138bc75d-0d04-0410-961f-82ee72b054a4