type_traits: Implement remove_const, remove_volatile, and remove_cv.

2004-12-10  Paolo Carlini  <pcarlini@suse.de>

	* include/tr1/type_traits: Implement remove_const, remove_volatile,
	and remove_cv.
	* testsuite/tr1/4_metaprogramming/const_volatile_modifications/
	remove_const.cc: New.
	* testsuite/tr1/4_metaprogramming/const_volatile_modifications/
	remove_cv.cc: Likewise.
	* testsuite/tr1/4_metaprogramming/const_volatile_modifications/
	remove_volatile.cc: Likewise.

	* testsuite/tr1/4_metaprogramming/primary_type_categories/
	is_array/is_array.cc: Slightly tweak consistently, remove typedefs,
	add a few tests.

From-SVN: r91990