cppfiles.c (NEVER_REREAD, [...]): Move from cpphash.h.

cppfiles.c (NEVER_REREAD, [...]): Move from cpphash.h.

        * cppfiles.c (NEVER_REREAD, DO_NOT_REREAD): Move from cpphash.h.
        * cpphash.h (NEVER_REREAD, DO_NOT_REREAD, ABSOLUTE_PATH): Delete.
        * cpplex.c (parse_identifier): Improve diagnostic.
        (_cpp_lex_token): Return unconditionally at the end of a directive.
        * cpplib.c (read_flag): Verify legality of each flag.
        (end_directive): Resotre pfile->skipping before skip_rest_of_line.
        (do_line): Use the new read_flag.
        * cppmacro.c (struct cpp_macro, parse_arg, replace_args,
        check_macro_redefinition, parse_params): Rename var_args to
        variadic.

From-SVN: r38150