message: fix(shell-evaluator): only apply async-rewriter2 runtime support once
  `hasAppliedAsyncWriterRuntimeSupport` was supposed to be a run-only
  guard, it was just the actual setting of the variable that was missing
  so far.
  This fix makes the shell respond a lot faster when using the new async
  rewriter. :)
diff: @@ -65,6 +65,7 @@ class ShellEvaluator<EvaluationResultType = ShellResult> {
  }
  if (!this.hasAppliedAsyncWriterRuntimeSupport) {
  + this.hasAppliedAsyncWriterRuntimeSupport = true;
  const supportCode = (this.internalState.asyncWriter as any).runtimeSupportCode();
  // Eval twice: We need the modified prototypes to be present in both
  // the evaluation context and the current one, because e.g. the value of
  