re PR rtl-optimization/23392 (foward-1.m fails with -funroll-loops -O3 -fgnu-runtime)

re PR rtl-optimization/23392 (foward-1.m fails with -funroll-loops -O3 -fgnu-runtime)

	PR rtl-optimization/23392
	* regrename.c (enum scan_actions) Add mark_access.
	(scan_actions_name): Ditto.
	(scan_rtx_reg): Handle mark_access.
	(scan_rtx_address): Do nothing for mark_access.
	(build_def_use): Mark source registers in REG_FRAME_RELATED_EXPR
	and regs in REG_INC notes before closing chains for dead regs.
	Mark destination regs in REG_FRAME_RELATED_EXPR notes after
	opening chains for new writes.

From-SVN: r107059