Parse eagerly inside block scopes.

test/mjsunit/regress/regress-4255-1.js

+// Copyright 2015 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// comments to trigger lazy compilation comments to trigger lazy compilation
+// comments to trigger lazy compilation comments to trigger lazy compilation
+// comments to trigger lazy compilation comments to trigger lazy compilation
+// comments to trigger lazy compilation comments to trigger lazy compilation
+// comments to trigger lazy compilation comments to trigger lazy compilation
+// comments to trigger lazy compilation comments to trigger lazy compilation
+// comments to trigger lazy compilation comments to trigger lazy compilation
+// comments to trigger lazy compilation comments to trigger lazy compilation
+// comments to trigger lazy compilation comments to trigger lazy compilation
+// comments to trigger lazy compilation comments to trigger lazy compilation
+// comments to trigger lazy compilation comments to trigger lazy compilation
+// comments to trigger lazy compilation comments to trigger lazy compilation
+// comments to trigger lazy compilation comments to trigger lazy compilation
+// comments to trigger lazy compilation comments to trigger lazy compilation
+// comments to trigger lazy compilation comments to trigger lazy compilation
+
+'use strict';
+{
+  let x = function() {};
+  // Trigger OSR.
+  for (var i = 0; i < 1000000; i++);
+}