PR c++/33506
	* langhooks.h (struct lang_hooks_for_types): Add type_hash_eq
	field.
	* langhooks-def.h (LANG_HOOKS_TYPE_HASH_EQ): Define.
	(LANG_HOOKS_FOR_TYPES_INITIALIZER): Add LANG_HOOKS_TYPE_HASH_EQ.
	* tree.c (type_hash_eq): For FUNCTION_TYPE use
	lang_hooks.type.type_hash_eq in addition to generic tests.

	* cp-tree.h (cxx_type_hash_eq): New prototype.
	* cp-objcp-common.h (LANG_HOOKS_TYPE_HASH_EQ): Redefine.
	* tree.c (cxx_type_hash_eq): New function.

	* g++.dg/ext/attrib29.C: New test.

From-SVN: r128718