Introduce extended mode.

test/mjsunit/harmony/debug-evaluate-blockscopes.js

Index: test/mjsunit/harmony/debug-evaluate-blockscopes.js
diff --git a/test/mjsunit/harmony/debug-evaluate-blockscopes.js b/test/mjsunit/harmony/debug-evaluate-blockscopes.js
index 06139d396557b7d168a2656fef44d3625a31a8e0..d6ce8b2b6a8c8050e1769297f865d06cf007bc6b 100644
--- a/test/mjsunit/harmony/debug-evaluate-blockscopes.js
+++ b/test/mjsunit/harmony/debug-evaluate-blockscopes.js
@@ -30,6 +30,12 @@
 // Test debug evaluation for functions without local context, but with
 // nested catch contexts.
 
+// TODO(ES6): properly activate extended mode
+"use strict";
+
+var x;
+var result;
+
 function f() {
   {                   // Line 1.
     let i = 1;        // Line 2.
@@ -42,7 +48,7 @@ function f() {
 };
 
 // Get the Debug object exposed from the debug context global object.
-Debug = debug.Debug
+var Debug = debug.Debug
 // Set breakpoint on line 6.
 var bp = Debug.setBreakPoint(f, 6);