Improve performance of invokevirtual/invokeinterface with embedded imt/vtable

Add an embedded version of imt/vtable into class object. Both tables start at
fixed offset within class object so method/entry point can be loaded directly
from class object for invokeinterface/invokevirtual.

Bug: 8142917
Change-Id: I4240d58cfbe9250107c95c0708c036854c455968
diff --git a/runtime/object_callbacks.h b/runtime/object_callbacks.h
index d8c1c40..0e6f4d8 100644
--- a/runtime/object_callbacks.h
+++ b/runtime/object_callbacks.h
@@ -26,10 +26,10 @@
 
 namespace art {
 namespace mirror {
-class Class;
-class Object;
-template<class MirrorType> class HeapReference;
-class Reference;
+  class Class;
+  class Object;
+  template<class MirrorType> class HeapReference;
+  class Reference;
 }  // namespace mirror
 class StackVisitor;