[turbofan] Fix OSR environment in for-in.

test/mjsunit/compiler/regress-607493.js

 // Copyright 2016 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-explicit-tailcalls
+// Flags: --allow-natives-syntax
 
-function f() {
-  return 1;
+var a = [1];
+
+function g() {
+  for (var x in a) {
+    try {
+      for (var i = 0; i < 10; i++) { %OptimizeOsr(); }
+      return;
+    } catch(e) {
+      continue;
+    }
+  }
 }
 
-function g() {
-  try {
-    try {
-      f();
-    } catch(e) {
-      return continue f();
-    }
-  } finally {
-    f();
-  }
-}
+g();