message: Clear reachability map after fusion.
diff: @@ -602,6 +602,9 @@ StatusOr<bool> InstructionFusion::Run(HloModule* module) {
  VLOG(1) << FusionConfigToString(*fusion_config);
  module->set_config(module_config);
  }
  +
  + reachability_.reset();
  +
  VLOG(1) << "Fusion count: " << fuse_count;
  return changed;
  