Add range-ops support for builtin functions.

Add range-ops support for builtin functions.

Convert CFN_BUILT_IN_CONSTANT_P as first POC.

	* gimple-range-fold.cc
	(fold_using_range::range_of_builtin_int_call): Remove case for
	CFN_BUILT_IN_CONSTANT_P.
	* gimple-range-op.cc (gimple_range_op_handler::supported_p):
	Check if a call also creates a range-op object.
	(gimple_range_op_handler): Also check builtin calls.
	(class cfn_constant_float_p): New.  Float CFN_BUILT_IN_CONSTANT_P.
	(class cfn_constant_p): New.  Integral CFN_BUILT_IN_CONSTANT_P.
	(gimple_range_op_handler::maybe_builtin_call): Set arguments and
	handler for supported built-in calls.
	* gimple-range-op.h (maybe_builtin_call): New prototype.