A Japanese-unfriendy error message contruction

Hello.

While I revised the translation, I ran across the following code.

> form_policy = (Form_pg_policy) GETSTRUCT(tuple);
>
> appendStringInfo(&buffer, _("policy %s on "),
> NameStr(form_policy->polname));
> getRelationDescription(&buffer, form_policy->polrelid);

getRelationDescription appends a string like "table %s" to the
buffer so finally a message like "policy %s on table %s" is
constructed but this is very unfriendly to Japanese syntax.

The "policy %s" and "<objname> %s" are transposed in Japaese
syntax. Specifically "<objname> %s NO <policy> %s" is the
natural translation of "policy %s on <objname> %s". But currently
we cannot get the natural error message in Japanese.

For the reason, I'd like to propose to refactor
getObjectDescription:OPCLASS_POLICY as the attached patch. The
same structure is seen for OPCLASS_AMOP.

regards.

--
Kyotaro Horiguchi
NTT Open Source Software Center