csa: Fix --enable-checking=yes,df bootstrap failure in csa [PR94961]

csa: Fix --enable-checking=yes,df bootstrap failure in csa [PR94961]

My recent combine-stack-adj.c change broke df checking bootstrap,
while most of the changes are done through validate_change/confirm_changes
which update df info, the removal of REG_EQUAL notes didn't update df info.

2020-05-08  Jakub Jelinek  <jakub@redhat.com>

	PR bootstrap/94961
	PR rtl-optimization/94516
	* rtl.h (remove_reg_equal_equiv_notes): Add a bool argument defaulted
	to false.
	* rtlanal.c (remove_reg_equal_equiv_notes): Add no_rescan argument.
	Call df_notes_rescan if that argument is not true and returning true.
	* combine.c (adjust_for_new_dest): Pass true as second argument to
	remove_reg_equal_equiv_notes.
	* postreload.c (reload_combine_recognize_pattern): Don't call
	df_notes_rescan.