e98e6a1198
Remove special case for null in message snapshots; snapshots are sometimes read or written with no current isolate group. Currently still all copies pointing into the VM isolate. TEST=ci Change-Id: I4d2e35a01880885d4e92e1c623c0f39a35e06065 Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/493866 Commit-Queue: Ryan Macnak <rmacnak@google.com> Reviewed-by: Alexander Aprelev <aam@google.com>