ART: Add dex::StringIndex

Add abstraction for uint32_t string index.

Test: m test-art-host
Change-Id: I917c2881702fe3df112c713f06980f2278ced7ed
diff --git a/runtime/runtime.cc b/runtime/runtime.cc
index ee4d669..e46b253 100644
--- a/runtime/runtime.cc
+++ b/runtime/runtime.cc
@@ -2023,7 +2023,8 @@
   preinitialization_transaction_->RecordWeakStringRemoval(s);
 }
 
-void Runtime::RecordResolveString(ObjPtr<mirror::DexCache> dex_cache, uint32_t string_idx) const {
+void Runtime::RecordResolveString(ObjPtr<mirror::DexCache> dex_cache,
+                                  dex::StringIndex string_idx) const {
   DCHECK(IsAotCompiler());
   DCHECK(IsActiveTransaction());
   preinitialization_transaction_->RecordResolveString(dex_cache, string_idx);