Implement rudimentary module linking.

src/factory.h

Index: src/factory.h
diff --git a/src/factory.h b/src/factory.h
index 786d4a983a4d6bba856337956474aac509e812e1..06aad1bef6b9ec6dce19b9616fb7221252208dab 100644
--- a/src/factory.h
+++ b/src/factory.h
@@ -162,9 +162,12 @@ class Factory {
   // Create a global (but otherwise uninitialized) context.
   Handle<Context> NewGlobalContext();
 
+  // Create a module context.
+  Handle<Context> NewModuleContext(Handle<Context> previous,
+                                   Handle<ScopeInfo> scope_info);
+
   // Create a function context.
-  Handle<Context> NewFunctionContext(int length,
-                                     Handle<JSFunction> function);
+  Handle<Context> NewFunctionContext(int length, Handle<JSFunction> function);
 
   // Create a catch context.
   Handle<Context> NewCatchContext(Handle<JSFunction> function,
@@ -177,7 +180,7 @@ class Factory {
                                  Handle<Context> previous,
                                  Handle<JSObject> extension);
 
-  // Create a 'block' context.
+  // Create a block context.
   Handle<Context> NewBlockContext(Handle<JSFunction> function,
                                   Handle<Context> previous,
                                   Handle<ScopeInfo> scope_info);
@@ -262,6 +265,9 @@ class Factory {
   // runtime.
   Handle<JSObject> NewJSObjectFromMap(Handle<Map> map);
 
+  // JS modules are pretenured.
+  Handle<JSModule> NewJSModule();
+
   // JS arrays are pretenured when allocated by the parser.
   Handle<JSArray> NewJSArray(int capacity,
                              ElementsKind elements_kind = FAST_ELEMENTS,