Martin von Zweigbergk <martinvonz@google.com> [Mon, 12 Mar 2018 15:50:25 -0700] rev 3561
amend: include "operation" metadata in obsmarkers
This is for the legacy handling support for "hg commit --amend"
case. I picked "amend" because it feels more natural than
"commit". Besides, and more importantly, that's consistent what core
uses.