b8aef62abd
Prior to this change, loading a dill with extensions in it twice, would mean getting the extension members twice. Change-Id: I766a4a6b0ade98ce9af803db0c696e64821e015a Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/121064 Commit-Queue: Jens Johansen <jensj@google.com> Reviewed-by: Johnni Winther <johnniwinther@google.com>