[es6] Fix completion values of for loops with lexical variables

test/mjsunit/es6/block-for.js

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 140 matching lines @@
   let a = [];
   for (let i = 0; i < 5; a.push(function () { return i; }), ++i) { }
   for (let k = 0; k < 5; ++k) {
     assertEquals(k + 1, a[k]());
   }
 }
 closure_in_for_next();
 
 
 // In a for-in statement the iteration variable is fresh
-// for earch iteration.
+// for each iteration.
 function closures3(x) {
   let a = [];
   for (let p in x) {
     a.push(function () { return p; });
   }
   let k = 0;
   for (let q in x) {
     assertEquals(q, a[k]());
     ++k;
   }
 }
 closures3({a : [0], b : 1, c : {v : 1}, get d() {}, set e(x) {}});
+
+// Check normal for statement completion values.
+assertEquals(1, eval("for (let i = 0; i < 10; i++) { 1; }"));
+assertEquals(9, eval("for (let i = 0; i < 10; i++) { i; }"));
+assertEquals(undefined, eval("for (let i = 0; false;) { }"));
+assertEquals(undefined, eval("for (const i = 0; false;) { }"));
+assertEquals(undefined, eval("for (let i = 0; i < 10; i++) { }"));
+assertEquals(undefined, eval("for (let i = 0; false;) { i; }"));
+assertEquals(undefined, eval("for (const i = 0; false;) { i; }"));
+assertEquals(undefined, eval("for (let i = 0; true;) { break; }"));
+assertEquals(undefined, eval("for (const i = 0; true;) { break; }"));
+assertEquals(undefined, eval("for (let i = 0; i < 10; i++) { continue; }"));
+assertEquals(undefined, eval("for (let i = 0; true;) { break; i; }"));
+assertEquals(undefined, eval("for (const i = 0; true;) { break; i; }"));
+assertEquals(undefined, eval("for (let i = 0; i < 10; i++) { continue; i; }"));
+assertEquals(0, eval("for (let i = 0; true;) { i; break; }"));
+assertEquals(0, eval("for (const i = 0; true;) { i; break; }"));
+assertEquals(9, eval("for (let i = 0; i < 10; i++) { i; continue; }"));
+assertEquals(3, eval("for (let i = 0; true; i++) { i; if (i >= 3) break; }"));
+assertEquals(2, eval("for (let i = 0; true; i++) { if (i >= 3) break; i; }"));
+assertEquals(
+  2, eval("for (let i = 0; i < 10; i++) { if (i >= 3) continue; i; }"));
+assertEquals(undefined, eval("foo: for (let i = 0; true;) { break foo; }"));
+assertEquals(undefined, eval("foo: for (const i = 0; true;) { break foo; }"));
+assertEquals(3, eval("foo: for (let i = 3; true;) { i; break foo; }"));