ART: Add dex::TypeIndex

Add abstraction for uint16_t type index.

Test: m test-art-host
Change-Id: I47708741c7c579cbbe59ab723c1e31c5fe71f83a
diff --git a/runtime/mirror/object_test.cc b/runtime/mirror/object_test.cc
index 5bf254d..4b47f7f 100644
--- a/runtime/mirror/object_test.cc
+++ b/runtime/mirror/object_test.cc
@@ -313,7 +313,7 @@
   ArtMethod* sort = java_util_Arrays->FindDirectMethod("sort", "([I)V", kRuntimePointerSize);
   const DexFile::TypeId* type_id = java_lang_dex_file_->FindTypeId("[I");
   ASSERT_TRUE(type_id != nullptr);
-  uint32_t type_idx = java_lang_dex_file_->GetIndexForTypeId(*type_id);
+  dex::TypeIndex type_idx = java_lang_dex_file_->GetIndexForTypeId(*type_id);
   Object* array = CheckAndAllocArrayFromCodeInstrumented(
       type_idx, 3, sort, Thread::Current(), false,
       Runtime::Current()->GetHeap()->GetCurrentAllocator());