Fix oat_test for portable path.

Change-Id: Ia5355488026692f9aeb76a6371239a2442c7a8ff
diff --git a/src/oat_test.cc b/src/oat_test.cc
index ae4aae2..788d1c7 100644
--- a/src/oat_test.cc
+++ b/src/oat_test.cc
@@ -125,7 +125,12 @@
   // If this test is failing and you have to update these constants,
   // it is time to update OatHeader::kOatVersion
   EXPECT_EQ(32U, sizeof(OatHeader));
+#if !defined(ART_USE_LLVM_COMPILER)
   EXPECT_EQ(32U, sizeof(OatMethodOffsets));
+#else
+  // ART-LLVM has a extra 4 bytes field: proxy_stub_offset_
+  EXPECT_EQ(36U, sizeof(OatMethodOffsets));
+#endif
 }
 
 }  // namespace art