Your changes to diagnostic machinery

[Gabriel Dos Reis]

Hi Kaveh,

  With your changes to have format-checking of diagnostics, it is no
longer possible to say things like

      pedwarn ("%H'%D' is not defined outside of function scope",
               &DECL_SOURCE_LOCATION (decl), decl);

in the C front end.  I'm getting:

  /home/gcc/src/egcs/gcc/c-common.c: In function `fname_decl':
  /home/gcc/src/egcs/gcc/c-common.c:1135: warning: unknown conversion type character `D' in format
  /home/gcc/src/egcs/gcc/c-common.c:1135: warning: too many arguments for format

which of course triggers a warning regression when bootstrapping.

%D is explicitly listed as diagnostic format specifiers. 
I'm going to temporary remove those attributes from the error() and
like unless you have plans to make the format-checking work... 

Thanks,

-- Gaby