message: Remove canonicalizer and extra breakup-islands passes at the end of the TPU bridge.
  As the end of the TPU bridge passes is preparing the IR for exporting back to Graph, having the canonicalizer run again is not be necessary as we want to preserve tf_executor.graph with single op tf_executor.islands.
diff: @@ -59,8 +59,6 @@ void CreateTPUBridge(OpPassManager &pm) {
  pm.addNestedPass<FuncOp>(CreateBreakUpIslandsPass());
  pm.addNestedPass<FuncOp>(TFDevice::CreateReplicateToIslandPass());
  pm.addNestedPass<FuncOp>(CreateBreakUpIslandsPass());
  - pm.addNestedPass<FuncOp>(createCanonicalizerPass());
  - pm.addNestedPass<FuncOp>(CreateBreakUpIslandsPass());
  }
  tensorflow::Status TPUBridge(ModuleOp module, bool enable_logging) {
  