Add initializer_list support as per N2679.

Add initializer_list support as per N2679.

        * include/debug/unordered_map: Add initializer_list support.
        * include/debug/safe_association.h: Likewise.
        * include/debug/unordered_set: Likewise.
        * include/debug/vector: Likewise.
        * include/debug/deque: Likewise.
        * include/debug/map.h: Likewise.
        * include/debug/set.h: Likewise.
        * include/debug/string: Likewise.
        * include/debug/list: Likewise.
        * include/debug/multimap.h: Likewise.
        * include/tr1_impl/unordered_map: Likewise.
        * include/tr1_impl/hashtable: Likewise.
        * include/tr1_impl/unordered_set: Likewise.
        * include/tr1_impl/regex: Likewise.
        * include/std/valarray: Likewise.
        * include/std/unordered_map: Likewise.
        * include/std/unordered_set: Likewise.
        * include/bits/stl_list.h: Likewise.
        * include/bits/stl_map.h: Likewise.
        * include/bits/stl_set.h: Likewise.
        * include/bits/basic_string.h: Likewise.
        * include/bits/basic_string.tcc: Likewise.
        * include/bits/stl_multimap.h: Likewise.
        * include/bits/stl_vector.h: Likewise.
        * include/bits/stl_deque.h: Likewise.
        * include/bits/stl_multiset.h: Likewise.
        * include/bits/stl_bvector.h: Likewise.
        * include/ext/vstring.h: Likewise.
        * include/ext/rc_string_base.h: Likewise.
        * include/ext/sso_string_base.h: Likewise.
        * src/Makefile.am (w?string-inst): Build with -std=gnu++0x.
        * src/Makefile.in: Likewise.
        * config/abi/pre/gnu.ver: Add new w?string exports.
...

From-SVN: r138043