Implement C++0x 'auto' semantics.

Implement C++0x 'auto' semantics.

        * decl.c (start_decl_1): Don't complain about auto being incomplete.
        (cp_finish_decl): Deduce auto.
        * init.c (build_new): Handle 'new auto'.
        * typeck2.c (cxx_incomplete_type_diagnostic): Give a different
        message for auto than for normal template type parms.
        * pt.c (type_dependent_expression_p): Handle { }.
        (make_auto): New function.
        (listify_autos): New function.
        (do_auto_deduction): New function.
        (is_auto): New function.
        (type_uses_auto): New function.
        * cp-tree.h: Declare them.
        * parser.c (cp_parser_decl_specifier_seq): In C++0x mode, don't
        treat auto as a declspec.
        (cp_parser_simple_type_specifier): It's a type-specifier.

From-SVN: r139798