Don't hardcode object layout in Unsafe and space_test.

Add a test for Unsafe.arrayBaseOffset() and Unsafe.arrayIndexScale().

Change-Id: I9cbdb79a4a7ee055129f41811a117910c8b2febd
diff --git a/test/Android.mk b/test/Android.mk
index d716f9b..4d47651 100644
--- a/test/Android.mk
+++ b/test/Android.mk
@@ -50,7 +50,8 @@
 	ParallelGC \
 	ReferenceMap \
 	StackWalk \
-	ThreadStress
+	ThreadStress \
+	UnsafeTest
 
 # TODO: Enable when the StackWalk2 tests are passing
 #	StackWalk2 \