objc-act.c (STRING_OBJECT_CLASS_NAME): Default to NSConstantString for NeXT-style...

objc-act.c (STRING_OBJECT_CLASS_NAME): Default to NSConstantString for NeXT-style runtimes.

        * objc/objc-act.c (STRING_OBJECT_CLASS_NAME): Default to
        NSConstantString for NeXT-style runtimes.
        (STRING_OBJECT_GLOBAL_NAME): New macro.
        (enum objc_tree_index): Add values OCTI_CNST_STR_GLOB_ID and
        OCTI_STRING_CLASS_DECL.
        (constant_string_global_id): New macro.
        (string_class_decl): Ditto.
        (setup_string_decl): New function.
        (build_objc_string_object): Use it to build a NeXT runtime
        compatible string initializer.

From-SVN: r41776