re PR debug/83157 (gcc.dg/guality/pr41616-1.c fail, inline instances refer to concrete instance as abstract origin)

	PR debug/83157
	* var-tracking.c (add_stores): Handle STRICT_LOW_PART SET_DEST.
	* cselib.c (cselib_record_sets): For STRICT_LOW_PART dest,
	lookup if dest in some wider mode is known to be const0_rtx and
	if so, record permanent equivalence for it to be ZERO_EXTEND of
	the narrower mode destination.

From-SVN: r259353