* crtstuff.c (__dso_handle): Declare.
	(__cxa_finalize): Likewise.
	(do_global_dtors_aux): Call __cxa_finalize if __dso_handle is
	non-NULL.

	* invoke.texi: Document -fuse-cxa-atexit.

	* tree.h (ptr_type_node): Document.
	(const_ptr_type_node): Likewise.

From-SVN: r30989