Always track arguments, even when ignoring equiv params.

Always track arguments, even when ignoring equiv params.

To "ignore" ranges from equivalences, we should track the range separately,
but still do the other name processing which determiens if there is a single
name or not for equivalence.  Otherwise we mistakently think we can introduce
an equivalences.

	gcc/
	PR tree-optimization/103440
	* gimple-range-fold.cc (fold_using_range::range_of_phi): Continue
	normal param processing for equiv params.

	gcc/testsuite/
	* gcc.dg/pr103440.c: New.