[PATCH] add some -Werror pragmas for tilegx

[Paul Eggert]

Chris Metcalf wrote:
> +          /* Using the tilegx gcc 4.8.2 yields uninitialized warnings
> +             here (on the "else if" line) and below.  Compiling the same
> +             source code with the same gcc version on x86_64 does not
> +             yield the warning, so it is something subtle.  */
> +          DIAG_PUSH_NEEDS_COMMENT;
> +          DIAG_IGNORE_NEEDS_COMMENT(4.8, "-Wmaybe-uninitialized");
>          }
>         else if (br_elem->type == COLL_SYM)
>          {
> +          DIAG_POP_NEEDS_COMMENT;

Can you fix this in a way that doesn't feel like ifdefs that are improperly 
nested with respect to the actual code?  E.g., by moving the "br_elem->type == 
COLL_SYM" expression into a static function, and playing with the pragmas only 
inside that function's body?