tree.h (alias_diag_flags): New enum.

        * 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.

From-SVN: r163425