Implement relational operators for frange with endpoints.

Implement relational operators for frange with endpoints.

This is the implementation of the relational range operators for
frange.  These are the core operations that require specific FP domain
knowledge.

gcc/ChangeLog:

	* range-op-float.cc (finite_operand_p): New.
	(build_le): New.
	(build_lt): New.
	(build_ge): New.
	(build_gt): New.
	(foperator_equal::fold_range): New implementation with endpoints.
	(foperator_equal::op1_range): Same.
	(foperator_not_equal::fold_range): Same.
	(foperator_not_equal::op1_range): Same.
	(foperator_lt::fold_range): Same.
	(foperator_lt::op1_range): Same.
	(foperator_lt::op2_range): Same.
	(foperator_le::fold_range): Same.
	(foperator_le::op1_range): Same.
	(foperator_le::op2_range): Same.
	(foperator_gt::fold_range): Same.
	(foperator_gt::op1_range): Same.
	(foperator_gt::op2_range): Same.
	(foperator_ge::fold_range): Same.
	(foperator_ge::op1_range): Same.
	(foperator_ge::op2_range): Same.

gcc/testsuite/ChangeLog:

	* gcc.dg/tree-ssa/recip-3.c: Avoid premature optimization so test
	has a chance to succeed.