PR rtl-optimization/28726
	* sched-deps.c (sched_analyze_reg): New function extracted from...
	(sched_analyze_1): ...here.  Call it to analyze references to
	registers.  Treat again writes to a stack register as writing to the
	register.
	(sched_analyze_2): ...and here.  Call it to analyze references to
	registers.  Treat again reads of a stack register as reading the
	register.

From-SVN: r116855