re PR libstdc++/46718 ([c++0x] nullptr_t must be scalar)

re PR libstdc++/46718 ([c++0x] nullptr_t must be scalar)

2010-11-30  Paolo Carlini  <paolo.carlini@oracle.com>

	PR libstdc++/46718
	* include/std/type_traits (__is_nullptr_t): Add.
	(is_scalar): Use the latter.
	* testsuite/20_util/is_scalar/value.cc: New.
	* testsuite/20_util/is_scalar/requirements/typedefs.cc: Likewise.
	* testsuite/20_util/is_scalar/requirements/explicit_instantiation.cc:
	Likewise.
	* testsuite/20_util/make_signed/requirements/typedefs_neg.cc:
	Adjust dg-error line numbers.
	* testsuite/20_util/make_unsigned/requirements/typedefs_neg.cc:
	Likewise.
	* testsuite/20_util/declval/requirements/1_neg.cc: Likewise.

From-SVN: r167294