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/optimizing/dead_code_elimination.cc b/compiler/optimizing/dead_code_elimination.cc
index e1bde7c..aa3f268 100644
--- a/compiler/optimizing/dead_code_elimination.cc
+++ b/compiler/optimizing/dead_code_elimination.cc
@@ -16,7 +16,7 @@
 
 #include "dead_code_elimination.h"
 
-#include "utils/array_ref.h"
+#include "base/array_ref.h"
 #include "base/bit_vector-inl.h"
 #include "ssa_phi_elimination.h"