As discussed on the phone, I'd like your thoughts on the...

src/assembler.cc

Index: src/assembler.cc
===================================================================
--- src/assembler.cc	(revision 645)
+++ src/assembler.cc	(working copy)
@@ -564,6 +564,10 @@
   return ExternalReference(Heap::NewSpaceAllocationTopAddress());
 }
 
+ExternalReference ExternalReference::heap_always_allocate_scope_depth() {
+  return ExternalReference(Heap::always_allocate_scope_depth_address());
+}
+
 ExternalReference ExternalReference::new_space_allocation_limit_address() {
   return ExternalReference(Heap::NewSpaceAllocationLimitAddress());
 }