re PR libstdc++/60333 (type_traits make_signed, make_unsigned missing support for long long enumerations)

	PR libstdc++/60333
	* include/std/type_traits (__make_unsigned_selector<_Tp, false, true>):
	Handle enumeration types larger than sizeof(long).
	(__make_signed_selector<_Tp, false, true>): Find unsigned type then
	make it signed.
	* testsuite/20_util/declval/requirements/1_neg.cc: Adjust dg-error.
	* testsuite/20_util/make_signed/requirements/typedefs_neg.cc:
	Likewise.
	* testsuite/20_util/make_signed/requirements/typedefs-3.cc: New.
	* testsuite/20_util/make_unsigned/requirements/typedefs_neg.cc: Adjust
	dg-error.
	* testsuite/20_util/make_unsigned/requirements/typedefs-3.cc: New.

From-SVN: r222526