merge: make low-level update() private (API) We have very few callers left that call the low-level `merge.update()` function. I think it's time to make it private. I'll remove the remaining callers in coming patches, except for one call from the `rebase` module. I hope to eventually fix that too, but it's more complex because it requires teaching `merge.graft()` to work with a dirty working copy. Differential Revision: https://phab.mercurial-scm.org/D9065

--- a/relnotes/next	Mon Sep 21 10:09:39 2020 -0700
+++ b/relnotes/next	Mon Sep 21 11:12:58 2020 -0700
@@ -20,3 +20,7 @@
 
 == Internal API Changes ==
 
+ * `merge.update()` is now private (renamed to `_update()`). Hopefully
+   the higher-level functions available in the same module cover your
+   use cases.
+