Handle a_2= &b properly in range calculations.

Handle a_2= &b properly in range calculations.

when processing assignments, we were using the type of b instead of type
of &b when computing a range.  This was usually filtered out by FRE.
turning it off exposed it.

	gcc/
	PR tree-optimization/97520
	* gimple-range.cc (range_of_non_trivial_assignment): Handle x = &a
	by returning a non-zero range.
	gcc/testsuite/
	* gcc.dg/pr97520.c: New.