Martin von Zweigbergk <martinvonz@google.com> [Tue, 20 Mar 2018 21:45:48 -0700] rev 37040
rebase: inline _makextrafn() now that we have only one caller
Also avoid even creating a function since we just end up calling it
right away.
Differential Revision: https://phab.mercurial-scm.org/D2918