Move megamorphic cache table into the Dart heap.

runtime/vm/object_store.h

Index: runtime/vm/object_store.h
diff --git a/runtime/vm/object_store.h b/runtime/vm/object_store.h
index e22a096a312ae6ee35ce8dd8f7b2b14094c7baad..3e34351b07556349aae54fdc0e6d67cb99fa6893 100644
--- a/runtime/vm/object_store.h
+++ b/runtime/vm/object_store.h
@@ -433,6 +433,19 @@ class ObjectStore {
     compile_time_constants_ = value.raw();
   }
 
+  RawGrowableObjectArray* megamorphic_cache_table() const {
+    return megamorphic_cache_table_;
+  }
+  void set_megamorphic_cache_table(const GrowableObjectArray& value) {
+    megamorphic_cache_table_ = value.raw();
+  }
+  RawFunction* megamorphic_miss_handler() const {
+    return megamorphic_miss_handler_;
+  }
+  void set_megamorphic_miss_handler(const Function& value) {
+    megamorphic_miss_handler_ = value.raw();
+  }
+
   // Visit all object pointers.
   void VisitObjectPointers(ObjectPointerVisitor* visitor);
 
@@ -523,8 +536,10 @@ class ObjectStore {
   RawFunction* handle_message_function_;
   RawArray* library_load_error_table_;
   RawArray* compile_time_constants_;
+  RawGrowableObjectArray* megamorphic_cache_table_;
+  RawFunction* megamorphic_miss_handler_;
   RawObject** to() {
-    return reinterpret_cast<RawObject**>(&compile_time_constants_);
+    return reinterpret_cast<RawObject**>(&megamorphic_miss_handler_);
   }
 
   friend class SnapshotReader;