prevent doubled diagnostics on symbol alias pairs

[Richard Henderson]

On 08/20/2010 09:59 AM, Olivier Hainque wrote:
> 2010-08-20  Olivier Hainque  <hainque@adacore.com>
> 
>         * tree.h (alias_diag_flags): New enum.
>         (alias_pair): Add an 'emitted_diags' field.
>         * varasm.c (finish_aliases_1): Honor and update p->emitted_diags.
>         (assemble_alias): Initialize emitted_diags of new pairs.

Ok.


r~