Fix remaining read barrier issues in image relocation

Added a way to disallow read barriers, this makes it easy to find
the issues.

Bug: 26786304
Change-Id: I7ebb50832686d03e096a979aae9741239371683f
diff --git a/runtime/mirror/iftable.h b/runtime/mirror/iftable.h
index 605deac..d6571f2 100644
--- a/runtime/mirror/iftable.h
+++ b/runtime/mirror/iftable.h
@@ -43,8 +43,11 @@
     return method_array;
   }
 
+  template<VerifyObjectFlags kVerifyFlags = kDefaultVerifyFlags,
+           ReadBarrierOption kReadBarrierOption = kWithReadBarrier>
   size_t GetMethodArrayCount(int32_t i) SHARED_REQUIRES(Locks::mutator_lock_) {
-    auto* method_array = down_cast<PointerArray*>(Get((i * kMax) + kMethodArray));
+    auto* method_array = down_cast<PointerArray*>(
+        Get<kVerifyFlags, kReadBarrierOption>((i * kMax) + kMethodArray));
     return method_array == nullptr ? 0u : method_array->GetLength();
   }