re PR rtl-optimization/32557 (internal compiler error: RTL check: expected code 'reg', have 'subreg' in rhs_regno, at rtl.h:956)

	PR rtl-optimization/32557
	* df-problems.c (df_note_bb_compute): Use mws->start_regno instead
	of REGNO (mws->mw_reg).

From-SVN: r127703