combine-stack-adj.c (combine_stack_adjustments_for_block): Do nothing for stack adjustments with REG_STACK_CHECK.

	* combine-stack-adj.c (combine_stack_adjustments_for_block): Do
	nothing for stack adjustments with REG_STACK_CHECK.
	* sched-deps.c (parse_add_or_inc): Reject insns with
	REG_STACK_CHECK from dependency breaking.
	* config/i386/i386.c (pro_epilogue_adjust_stack): Return insn.
	(ix86_adjust_satck_and_probe_stack_clash): Add REG_STACK_NOTEs.
	* reg-notes.def (STACK_CHECK): New note.

	* gcc.target/i386/stack-check-11.c: New test.

From-SVN: r252999