Separate oat from image

Change-Id: If2abdb99826ead14e3465d90ba2acffd89709389
diff --git a/src/stub_arm.cc b/src/stub_arm.cc
index a35bfe2..75d60f5 100644
--- a/src/stub_arm.cc
+++ b/src/stub_arm.cc
@@ -36,6 +36,7 @@
   size_t cs = assembler->CodeSize();
   ByteArray* abstract_stub = ByteArray::Alloc(cs);
   CHECK(abstract_stub != NULL);
+  CHECK(abstract_stub->GetClass()->GetDescriptor());
   MemoryRegion code(abstract_stub->GetData(), abstract_stub->GetLength());
   assembler->FinalizeInstructions(code);