message: Fix ambiguous JSON value
  Summary: Explicitly cast to `Json::Int64` to avoid ambiguity.
diff: @@ -602,7 +602,7 @@ Json::Value get_pass_stats(const PassManager& mgr) {
  }
  Json::Value pass;
  for (const auto& pass_metric : pass_info.metrics) {
  - pass[pass_metric.first] = pass_metric.second;
  + pass[pass_metric.first] = (Json::Int64)pass_metric.second;
  }
  all[pass_info.name] = pass;
  }
  