Check that Class::AllocObject is not used with arrays

Change-Id: I1286c59f0528353bcffce56af473509efdf2c4fa
diff --git a/src/object.cc b/src/object.cc
index 78a1976..343f643 100644
--- a/src/object.cc
+++ b/src/object.cc
@@ -767,7 +767,9 @@
   DCHECK(!IsAbstract()) << PrettyClass(this);
   DCHECK(!IsInterface()) << PrettyClass(this);
   DCHECK(!IsPrimitive()) << PrettyClass(this);
+  DCHECK(!IsArrayClass()) << PrettyClass(this);
   DCHECK(!Runtime::Current()->IsStarted() || IsInitializing()) << PrettyClass(this);
+  DCHECK_GE(this->object_size_, sizeof(Object));
   return Heap::AllocObject(this, this->object_size_);
 }