[VM] Type _CompactIterator/_CompactIterable._table
[VM] Type _CompactIterator/_CompactIterable._table

With the [_table] field being `dynamic` we were unable to eliminate
checks for the [_isModifiedSince] method, since there is a dynamic call
site.

This CL adds a type to [_table] so [_isModifiedSince] does not need to
perform any checks (via package:vm/transf.../no_dynamic_invocations_annotator.dart)

Issue https://github.com/dart-lang/sdk/issues/31798

Change-Id: If773c4b63fab62d1ccdd2e783aa16c19f780000a
Reviewed-on: https://dart-review.googlesource.com/43423
Commit-Queue: Martin Kustermann <a35dd5b79fac84b2bb3b026a16b8becc55af5961@google.com>
Reviewed-by: Vyacheslav Egorov <72c81f38df725d8f1832acb9b5bb99563fc2f1b9@google.com>

dartino/dart-sdk,dartino/dart-sdk,dartino/dart-sdk,dartino/dart-sdk,dart-lang/sdk,dart-lang/sdk,dart-archive/dart-sdk,dart-lang/sdk,dartino/dart-sdk,dart-archive/dart-sdk,dart-archive/dart-sdk,dartino/dart-sdk,dart-archive/dart-sdk,dart-archive/dart-sdk,dart-lang/sdk,dart-archive/dart-sdk,dart-archive/dart-sdk,dart-lang/sdk,dart-lang/sdk,dartino/dart-sdk,dart-archive/dart-sdk,dart-lang/sdk,dartino/dart-sdk,dartino/dart-sdk,dart-archive/dart-sdk,dart-lang/sdk