* cpplib.h (struct cpp_options): Add warn_deprecated field.
        * cppinit.c (cpp_create_reader): Turn it on by default.
        * c-opts.c (c_common_decode_option): Set it.
        * cpplib.c (do_pragma_once): Only complain about #pragma once
        if warn_deprecated is set.

From-SVN: r62005