[VM] Cleanup more typing issues in convert_patch.
[VM] Cleanup more typing issues in convert_patch.

Bug: https://github.com/dart-lang/sdk/issues/31052
Change-Id: Id39d6e44f49b539a5416ea6f5f62f252ee5a4c94
Reviewed-on: https://dart-review.googlesource.com/15122
Reviewed-by: Erik Corry <b520ba1e7f871f909b0b4a9e1cf9a391adc0e954@google.com>
Commit-Queue: Vyacheslav Egorov <72c81f38df725d8f1832acb9b5bb99563fc2f1b9@google.com>

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