Request for comments on overall approach.

runtime/vm/class_table.h

Index: runtime/vm/class_table.h
diff --git a/runtime/vm/class_table.h b/runtime/vm/class_table.h
index e96210615c225ab76b8d15ece988ce3459c3d3c9..05dcef033cd09efe45500be0b3726fcba154d231 100644
--- a/runtime/vm/class_table.h
+++ b/runtime/vm/class_table.h
@@ -7,6 +7,7 @@
 
 #include "platform/assert.h"
 #include "platform/globals.h"
+#include "vm/globals.h"
 
 namespace dart {
 
@@ -34,6 +35,10 @@ class ClassTable {
 
   void Print();
 
+  static intptr_t table_offset() {
+    return OFFSET_OF(ClassTable, table_);
+  }
+
  private:
   static const int initial_capacity_ = 512;
   static const int capacity_increment_ = 256;