Re: backpatch tests: Rename conflicting role names to 14/15

> > I can prepare the patches if there are no objections.
>
> If you could prepare a patch, that would be great!  Let's do that if
> v14 and v15 can also face the issue under a high-concurrent build.
> The blast area of 6a20b04f0408 is not that bad.

"make-installcheck --jobs 8" has reproduced the conflict almost
consistently between adminpack and plperl tests.

cherry-pick to 15 had no conflicts. 14 does not have the
plperl_setup_scratch schema, so I had to fix that.

See the attached.

--
Sami Imseih
Amazon Web Services