c-pragma.c (handle_pragma_token): Generate warning messages about unknown pragmas...

c-pragma.c (handle_pragma_token): Generate warning messages about unknown pragmas if warn_unknown_pragmas is set.

        * c-pragma.c (handle_pragma_token): Generate warning messages
        about unknown pragmas if warn_unknown_pragmas is set.
        * c-decl.c (c_decode_option): Parse -Wunknown-pragmas command
        line option to set variable: warn_unknown_pragmas.

From-SVN: r17168