re PR middle-end/54921 (wrong code with -Os -fno-omit-frame-pointer -fsched2-use...

re PR middle-end/54921 (wrong code with -Os -fno-omit-frame-pointer -fsched2-use-superblocks -fstack-protector -ftree-slp-vectorize)

	PR rtl-optimization/54921
	* cselib.h (fp_setter_insn): New prototype.
	* cselib.c (fp_setter_insn): New function.
	(cselib_process_insn): If frame_pointer_needed,
	call cselib_invalidate_rtx (stack_pointer_rtx) after
	processing a frame pointer setter.
	* var-tracking.c (fp_setter): Removed.
	(vt_initialize): Use fp_setter_insn instead of fp_setter.

	* gcc.dg/pr54921.c: New test.

From-SVN: r193647