pg_parg system table is suffering from software rot

Does anyone know what the system table pg_parg is, was, or might be
used for?

A comment at the head of include/catalog/pg_parg.h says

* [whatever this relation was, it doesn't seem to be used anymore --djm]

and as far as I can tell this is true --- the source code contains
no references to pg_parg or any of the field names therein. The table
is utterly undocumented, but it looks like it might once in the distant
past have represented proc argument types, which we now keep elsewhere.

The table is suffering from bit rot, in that its "parproid" field
contains OIDs of rows in both pg_proc and pg_operator. Rather than
trying to intuit what it is for enough to fix this, I propose just
deleting the darn thing. Do I hear any objections?

regards, tom lane