Precompilation: Generate instance calls as IC calls that can switch to Megamoprhic calls.

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 721669b91b8391ab86cf90860f6e3056ac1109b6..fd3c738918fa393a5f16844f6c176ef69efd9db8 100644
--- a/runtime/vm/object_store.h
+++ b/runtime/vm/object_store.h
@@ -449,6 +449,9 @@ class ObjectStore {
   void set_megamorphic_cache_table(const GrowableObjectArray& value) {
     megamorphic_cache_table_ = value.raw();
   }
+  RawCode* megamorphic_miss_code() const {
+    return megamorphic_miss_code_;
+  }
   RawFunction* megamorphic_miss_function() const {
     return megamorphic_miss_function_;
   }