range-op-float: Further foperator_{,not_}equal::fold_range fix

range-op-float: Further foperator_{,not_}equal::fold_range fix

On Fri, Mar 31, 2023 at 12:45:10PM +0200, Jakub Jelinek via Gcc-patches wrote:
>    - there is a missing case (not handled in this patch) where both operands
>      are known to be zeros, but not singleton zeros

This patch adds those cases.

2023-04-01  Jakub Jelinek  <jakub@redhat.com>

	* range-op-float.cc (foperator_equal::fold_range): If at least
	one of the op ranges is not singleton and neither is NaN and all
	4 bounds are zero, return [1, 1].
	(foperator_not_equal::fold_range): In the same case return [0, 0].