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/assembler.h b/compiler/utils/assembler.h
index b616057..314ff8c 100644
--- a/compiler/utils/assembler.h
+++ b/compiler/utils/assembler.h
@@ -24,6 +24,7 @@
 #include "arm/constants_arm.h"
 #include "base/arena_allocator.h"
 #include "base/arena_object.h"
+#include "base/array_ref.h"
 #include "base/enums.h"
 #include "base/logging.h"
 #include "base/macros.h"
@@ -33,7 +34,6 @@
 #include "memory_region.h"
 #include "mips/constants_mips.h"
 #include "offsets.h"
-#include "utils/array_ref.h"
 #include "x86/constants_x86.h"
 #include "x86_64/constants_x86_64.h"