* c-common.h (objc_build_method_signature): Update prototype.
* stub-objc.c (objc_build_method_signature): Update the stub
implementation to accept and ignore additional parameter.
* c-parser.c (c_parser_objc_method_decl): Reorgnize to pass
the value of ellipsis to objc_build_method_signature instead
of setting TREE_OVERFLOW on the parms TREE_LIST node.
* objc-act.h (METHOD_ADD_ARGS_ELLIPSIS_P): New macro for accessing
this field of an objc method decl.
* objc-act.c (build_method_decl): Take an additional "ellipsis"
argument, and set METHOD_ADD_ARGS_ELLIPSIS_P as appropriate.
(objc_build_method_signature): Accept additional "ellipsis"
argument and pass it to build_method_decl.
(get_arg_type_list, start_method_def, gen_method_decl): Use
the new METHOD_ADD_ARGS_ELLIPSIS_P instead of examining the
TREE_OVERFLOW field of a TREE_LIST node.