pg_upgrade in 9.5 broken for adminpack

pg_upgrade was recently broken for use upgrading from a system with
adminpack installed.

Breaking commit is:

commit 30982be4e5019684e1772dd9170aaa53f5a8e894
Author: Peter Eisentraut <peter_e(at)gmx(dot)net>

Integrate pg_upgrade_support module into backend

from pg_upgrade_dump_12870.log

pg_restore: creating EXTENSION "adminpack"
pg_restore: creating COMMENT "EXTENSION "adminpack""
pg_restore: [archiver (db)] Error while PROCESSING TOC:
pg_restore: [archiver (db)] Error from TOC entry 2806; 0 0 COMMENT
EXTENSION "adminpack"
pg_restore: [archiver (db)] could not execute query: ERROR: extension
"adminpack" does not exist
Command was: COMMENT ON EXTENSION "adminpack" IS 'administrative
functions for PostgreSQL';

I get the same error whether the source database is 9.2.10 or 9.5.HEAD.

Cheers,

Jeff