Use GORI to evaluate arguments of a COND_EXPR.

Use GORI to evaluate arguments of a COND_EXPR.

Provide an API into gori to perform a basic evaluation of the arguments of a
COND_EXPR if they are in the dependency chain of the condition.

	PR tree-optimization/104526
	gcc/
	* gimple-range-fold.cc (fold_using_range::range_of_cond_expr): Call
	new routine.
	* gimple-range-gori.cc (range_def_chain::get_def_chain): Force a build
	of dependency chain if there isn't one.
	(gori_compute::condexpr_adjust): New.
	* gimple-range-gori.h (class gori_compute): New prototype.

	gcc/testsuite/
	* gcc.dg/pr104526.c: New.