type_traits: Add the trivial is_union and is_class; add the __is_union_or_class exten...

type_traits: Add the trivial is_union and is_class; add the __is_union_or_class extension.

2005-02-25  Paolo Carlini  <pcarlini@suse.de>

	* include/tr1/type_traits: Add the trivial is_union and is_class;
	add the __is_union_or_class extension.
	(is_enum, is_empty): Use the latter.
	* include/tr1/type_traits_fwd.h: Add __is_union_or_class.
	* testsuite/testsuite_tr1.h: Add UnionType; trivial formatting
	fixes.
	* testsuite/tr1/4_metaprogramming/composite_type_traits/
	is_union_or_class/is_union_or_class.cc: New.
	* testsuite/tr1/4_metaprogramming/composite_type_traits/
	is_union_or_class/typedefs.cc: Likewise.

From-SVN: r95541