Add check to catch use dalvik's libcore earlier

Change-Id: Ic776ee35aead930157500f99049101786b3ee187
diff --git a/src/class_linker.cc b/src/class_linker.cc
index 52ce964..cfad9d1 100644
--- a/src/class_linker.cc
+++ b/src/class_linker.cc
@@ -3548,6 +3548,7 @@
   } else {
     klass->SetNumReferenceInstanceFields(num_reference_fields);
     if (!klass->IsVariableSize()) {
+      DCHECK_GE(size, sizeof(mirror::Object)) << ClassHelper(klass.get(), this).GetDescriptor();
       klass->SetObjectSize(size);
     }
   }