ART: Add dex::TypeIndex

Add abstraction for uint16_t type index.

Test: m test-art-host
Change-Id: I47708741c7c579cbbe59ab723c1e31c5fe71f83a
diff --git a/runtime/dex_cache_resolved_classes.h b/runtime/dex_cache_resolved_classes.h
index 0febbed..f53ca4a 100644
--- a/runtime/dex_cache_resolved_classes.h
+++ b/runtime/dex_cache_resolved_classes.h
@@ -21,6 +21,8 @@
 #include <unordered_set>
 #include <vector>
 
+#include "dex_file_types.h"
+
 namespace art {
 
 // Data structure for passing around which classes belonging to a dex cache / dex file are resolved.
@@ -59,7 +61,7 @@
     return location_checksum_;
   }
 
-  const std::unordered_set<uint16_t>& GetClasses() const {
+  const std::unordered_set<dex::TypeIndex>& GetClasses() const {
     return classes_;
   }
 
@@ -68,7 +70,7 @@
   const std::string base_location_;
   const uint32_t location_checksum_;
   // Array of resolved class def indexes.
-  mutable std::unordered_set<uint16_t> classes_;
+  mutable std::unordered_set<dex::TypeIndex> classes_;
 };
 
 inline bool operator<(const DexCacheResolvedClasses& a, const DexCacheResolvedClasses& b) {