* cvt.c (convert_lvalue): New fn.
        * cp-tree.h: Declare it.
        * method.c (do_build_assign_ref): Use it.
        (do_build_copy_constructor): Convert parm to base types
        before calling base constructors.

        * typeck.c (check_return_expr): Check DECL_ALIGN instead of
        DECL_USER_ALIGN.  Check flag_elide_constructors instead of
        optimize.
        * semantics.c (cp_expand_stmt): Don't destroy the named return value.

From-SVN: r43780