Re: Residual cleanups for tied objects in PL/Perl

I wrote:
> We still have multiple
> patterns for iterating through hashes: why do a couple of places use
> hv_iternextsv when the others don't? And why do we use hek2cstr
> in some places and not others?

Here's a patch to try to clean that up. I think it is wrong that
the extension modules don't use hek2cstr, so I made them do so.
(But we probably shouldn't back-patch that: it's a user-visible
behavioral change and we've not gotten actual field complaints AFAIR.)

> (oh, and for extra credit: why is there a second call of hv_iterinit
> in plperl_build_tuple_result and plperl_modify_tuple?)

That seems to be just cargo-culted, so I removed those calls.

regards, tom lane