Fix test with libarttest.so.

We used to always skip it as kIsDebugBuild was true for
libarttest.so and libarttestd.so.

Change-Id: I1a5efbba8c2f9d63af824ed727154794aaea8d29
diff --git a/test/566-polymorphic-inlining/src/Main.java b/test/566-polymorphic-inlining/src/Main.java
index 286f0d9..a59ce5b 100644
--- a/test/566-polymorphic-inlining/src/Main.java
+++ b/test/566-polymorphic-inlining/src/Main.java
@@ -98,6 +98,7 @@
   public static native void ensureJittedAndPolymorphicInline();
 
   public void increment() {
+    field.getClass(); // null check to ensure we get an inlined frame in the CodeInfo
     counter++;
   }
   public static int counter = 0;