Change fold_range to return a boolean result.

Change fold_range to return a boolean result.

2019-11-14  Andrew MacLeod  <amacleod@redhat.com>

	* range-op.h (range_operator::fold_range): Return a bool.
	* range-op.cc (range_operator::wi_fold): Assert supported type.
	(range_operator::fold_range): Assert supported type and return true.
	(operator_equal::fold_range): Return true.
	(operator_not_equal::fold_range): Same.
	(operator_lt::fold_range): Same.
	(operator_le::fold_range): Same.
	(operator_gt::fold_range): Same.
	(operator_ge::fold_range): Same.
	(operator_plus::op1_range): Adjust call to fold_range.
	(operator_plus::op2_range): Same.
	(operator_minus::op1_range): Same.
	(operator_minus::op2_range): Same.
	(operator_exact_divide::op1_range): Same.
	(operator_lshift::fold_range): Return true and adjust fold_range call.
	(operator_rshift::fold_range): Same.
	(operator_cast::fold_range): Return true.
	(operator_logical_and::fold_range): Same.
	(operator_logical_or::fold_range): Same.
	(operator_logical_not::fold_range): Same.
	(operator_bitwise_not::fold_range): Adjust call to fold_range.
	(operator_bitwise_not::op1_range): Same.
	(operator_cst::fold_range): Return true.
	(operator_identity::fold_range): Return true.
	(operator_negate::fold_range): Return true and adjust fold_range call.
	(operator_addr_expr::fold_range): Return true.
	(operator_addr_expr::op1_range): Adjust call to fold_range.
	(range_cast): Same.
	* tree-vrp.c (range_fold_binary_symbolics_p): Adjust call to fold_range.
	(range_fold_unary_symbolics_p): Same.

From-SVN: r278266