Merge branch 'jk/patch-ids-no-merges' into maint

"git log --cherry-pick" used to include merge commits as candidates to be matched up with other commits, resulting a lot of wasted time. The patch-id generation logic has been updated to ignore merges to avoid the wastage. * jk/patch-ids-no-merges: patch-ids: refuse to compute patch-id for merge commit patch-ids: turn off rename detection