Move ArrayRef to runtime/base

Will be used in upcoming CLs regarding VDEX and VerifierDeps.

Test: m test-art-host
Change-Id: I68e611a4a52246c2bdf45eab7c61f3212908afd4
diff --git a/compiler/utils/arm/assembler_thumb2.h b/compiler/utils/arm/assembler_thumb2.h
index 13f3bec..353555d 100644
--- a/compiler/utils/arm/assembler_thumb2.h
+++ b/compiler/utils/arm/assembler_thumb2.h
@@ -22,11 +22,11 @@
 #include <vector>
 
 #include "base/arena_containers.h"
+#include "base/array_ref.h"
 #include "base/logging.h"
 #include "constants_arm.h"
 #include "utils/arm/managed_register_arm.h"
 #include "utils/arm/assembler_arm.h"
-#include "utils/array_ref.h"
 #include "offsets.h"
 
 namespace art {