* include/bits/alloc_traits.h (__alloc_rebind): Define alias template.
	* include/bits/forward_list.h (_Fwd_list_base): Use __alloc_rebind.
	* include/bits/hashtable_policy.h (_Insert_base, _Hashtable_alloc):
	Likewise.
	* include/ext/alloc_traits.h: Fix comment.

From-SVN: r211995