* include/std/type_traits (__cpp_lib_bounded_array_traits): Define.
	* include/std/version (__cpp_lib_bounded_array_traits): Likewise.
	* testsuite/20_util/is_bounded_array/value.cc: Check for macro.
	* testsuite/20_util/is_unbounded_array/value.cc: Likewise.

From-SVN: r269426