* c-lex.c (lex_number): Only warn traditionally for U suffix
        outside system macros.
        * cppexp.c (parse_number): Similarly.
        * cpplib.h (NODE_SYSHDR, cpp_sys_objmacro_p): New.
        * cppmacro.c (struct cpp_macro): New member node.
        (parse_args): Only warn about missing rest args if not
        a system macro.
        (funlike_invocation_p): Similarly for uninvoked funlike macros.
        (cpp_sys_objmacro_p): New.
        (_cpp_create_definition): Store the node with the macro defn.
        Remember if the macro is defined in a system header.

From-SVN: r39661