harmony-scoping: Implement debugger support for script scope.

src/mirror-debugger.js

Index: src/mirror-debugger.js
diff --git a/src/mirror-debugger.js b/src/mirror-debugger.js
index c8d2461d6bf46f30c608b836adba3a78f2ed191f..affe43b693b2d8bbd52dacdad732aeea994d0023 100644
--- a/src/mirror-debugger.js
+++ b/src/mirror-debugger.js
@@ -193,13 +193,16 @@ PropertyAttribute.DontEnum   = DONT_ENUM;
 PropertyAttribute.DontDelete = DONT_DELETE;
 
 
-// A copy of the scope types from runtime.cc.
+// A copy of the scope types from runtime-debug.cc.
+// NOTE: these constants should be backward-compatible, so
+// add new ones to the end of this list.
 var ScopeType = { Global: 0,
                   Local: 1,
                   With: 2,
                   Closure: 3,
                   Catch: 4,
-                  Block: 5 };
+                  Block: 5,
+                  Script: 6 };
 
 
 // Mirror hierarchy:
@@ -2293,11 +2296,12 @@ ScopeMirror.prototype.scopeType = function() {
 
 
 ScopeMirror.prototype.scopeObject = function() {
-  // For local and closure scopes create a transient mirror as these objects are
-  // created on the fly materializing the local or closure scopes and
-  // therefore will not preserve identity.
+  // For local, closure and script scopes create a transient mirror
+  // as these objects are created on the fly materializing the local
+  // or closure scopes and therefore will not preserve identity.
   var transient = this.scopeType() == ScopeType.Local ||
-                  this.scopeType() == ScopeType.Closure;
+                  this.scopeType() == ScopeType.Closure ||
+                  this.scopeType() == ScopeType.Script;
   return MakeMirror(this.details_.object(), transient);
 };