ART: Add dex::TypeIndex

Add abstraction for uint16_t type index.

Test: m test-art-host
Change-Id: I47708741c7c579cbbe59ab723c1e31c5fe71f83a
diff --git a/runtime/interpreter/interpreter.cc b/runtime/interpreter/interpreter.cc
index a32c800..1b3d339 100644
--- a/runtime/interpreter/interpreter.cc
+++ b/runtime/interpreter/interpreter.cc
@@ -543,7 +543,7 @@
           ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
           // This is a suspend point. But it's ok since value has been set into shadow_frame.
           ObjPtr<mirror::Class> klass = class_linker->ResolveType(
-              instr->VRegB_21c(), shadow_frame->GetMethod());
+              dex::TypeIndex(instr->VRegB_21c()), shadow_frame->GetMethod());
           DCHECK(klass->IsStringClass());
         }
       } else {