[kernel] Remove unused GlobalIndexer from ast_to_binary.dart
[kernel] Remove unused GlobalIndexer from ast_to_binary.dart

Change-Id: Ide2b8997d831f811fa278164a25139ea1fde0c5f
Reviewed-on: https://dart-review.googlesource.com/55460
Reviewed-by: Kevin Millikin <a6737c91ef81c790d8ad0ae8762bd5b2332a6e42@google.com>
Commit-Queue: Jens Johansen <05223a3c6bdf76af6f84755eae231abeebcf4530@google.com>

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