ART: Add dex::TypeIndex

Add abstraction for uint16_t type index.

Test: m test-art-host
Change-Id: I47708741c7c579cbbe59ab723c1e31c5fe71f83a
diff --git a/runtime/oat_file.cc b/runtime/oat_file.cc
index c14b616..b120a69 100644
--- a/runtime/oat_file.cc
+++ b/runtime/oat_file.cc
@@ -38,6 +38,7 @@
 #include "base/stl_util.h"
 #include "base/systrace.h"
 #include "base/unix_file/fd_file.h"
+#include "dex_file_types.h"
 #include "elf_file.h"
 #include "elf_utils.h"
 #include "gc_root.h"
@@ -1342,7 +1343,7 @@
   }
   const DexFile::TypeId* type_id = dex_file.FindTypeId(descriptor);
   if (type_id != nullptr) {
-    uint16_t type_idx = dex_file.GetIndexForTypeId(*type_id);
+    dex::TypeIndex type_idx = dex_file.GetIndexForTypeId(*type_id);
     return dex_file.FindClassDef(type_idx);
   }
   return nullptr;