Merge branch 'master' into stable-5.12

Merge branch 'master' into stable-5.12

* master:
  [merge] Hide changes between ancestor and current for cherry-pick
  [merge] Use working tree filtered to 'ours' as input for conflicts
  [merge] Refactor choosing between working tree and stage 2
  [merge] Use EFS-linked IResources for non-workspace files
  [merge] Detect conflicting files underneath ignored folders
  [merge] Fix base for cherry-picks and rebases
  [merge] Record in index whether conflicting file has been updated
  Update Orbit to S20210518003616 and ant to 1.10.10.v20210426-1926
  [test] Try to stabilize StagingViewTest
  Update site: link to N&N

Change-Id: Ie66900f7139b9fd08938c023d0e9ba8de9c73ecd