* include/bits/stl_bvector.h (_Bvector_alloc_base): Eliminate.
        (_Bvector_base): Inherit directly from word allocator.
        * include/bits/stl_tree.h (_Rb_tree_alloc_base): Eliminate.
        (_Rb_tree_base): Eliminate.
        (_Rb_tree): Inherit directly from node allocator.
        * include/ext/slist (_Alist_alloc_base): Eliminate.
        (_Slist_base): Inherit direcly from node allocator.

From-SVN: r74955