Preliminary code for block scopes and block contexts.

src/factory.h

Index: src/factory.h
diff --git a/src/factory.h b/src/factory.h
index 3217ca906b37cda09da77c2195f4b5eb9850e874..a69b05b38f00fc385b665bba6eea1ea039b3fb24 100644
--- a/src/factory.h
+++ b/src/factory.h
@@ -167,6 +167,11 @@ class Factory {
                                  Handle<Context> previous,
                                  Handle<JSObject> extension);
 
+  // Create a 'block' context.
+  Handle<Context> NewBlockContext(Handle<JSFunction> function,
+                                  Handle<Context> previous,
+                                  Handle<SerializedScopeInfo> scope_info);
+
   // Return the Symbol matching the passed in string.
   Handle<String> SymbolFromString(Handle<String> value);
 
@@ -277,6 +282,8 @@ class Factory {
       Handle<Context> context,
       PretenureFlag pretenure = TENURED);
 
+  Handle<SerializedScopeInfo> NewSerializedScopeInfo(int length);
+
   Handle<Code> NewCode(const CodeDesc& desc,
                        Code::Flags flags,
                        Handle<Object> self_reference,