VRP should only recompute known statements.

VRP should only recompute known statements.

GORI should only recompute ranges for range-op statements that are known
to be safe.   Disable it for builtin_constant_p.

	PR tree-optimization/123205
	gcc/
	* gimple-range-gori.cc (gori_compute::may_recompute_p): Only
	recompute range-op statements.
	* gimple-range-op.cc (gimple_range_op_handler): Default
	recomputation to true.
	(maybe_builtin_call): CFN_BUILT_IN_CONSTANT_P should not be
	recomputable.
	* gimple-range-op.h (recomputable_p): New.
	(recomputable_p): New.

	gcc/testsuite/
	* gcc.dg/pr123205.c: New.