message: fix combination of ad_enabled() and ek.suspend/resume_grad
diff: @@ -753,7 +753,7 @@ template <typename T> bool ad_enabled() noexcept(true) {
  const Scope &scope = scopes.back();
  // Check if AD is disabled on the current thread
  - if (scope.complement && scope.indices.empty())
  + if (!scope.complement && scope.indices.empty())
  return false;
  }
  