Fix function scoping issue

test/mjsunit/regress/regress-520029.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.
+
+// Flags: --harmony-sloppy-let --harmony-sloppy
+
+// Test that hoisting a function out of a lexical scope does not
+// lead to a parsing error
+
+// This used to cause a crash in the parser
+function f(one) { class x { } { class x { } function g() { one; x; } g() } } f()
+
+// This used to lead to a ReferenceError
+function g() { var x = 1; { let x = 2; function g() { x; } g(); } }
+assertEquals(undefined, g());
+
+// This used to cause a crash in the parser
+function __f_4(one) {
+  var __v_10 = one + 1;
+  {
+    let __v_10 = one + 3;
+    function __f_6() {
+ one;
+ __v_10;
+    }
+    __f_6();
+  }
+}
+__f_4();