ART: Add dex::StringIndex

Add abstraction for uint32_t string index.

Test: m test-art-host
Change-Id: I917c2881702fe3df112c713f06980f2278ced7ed
diff --git a/runtime/class_linker.cc b/runtime/class_linker.cc
index 216ec9e..f98f364 100644
--- a/runtime/class_linker.cc
+++ b/runtime/class_linker.cc
@@ -7557,7 +7557,7 @@
 }
 
 mirror::String* ClassLinker::ResolveString(const DexFile& dex_file,
-                                           uint32_t string_idx,
+                                           dex::StringIndex string_idx,
                                            Handle<mirror::DexCache> dex_cache) {
   DCHECK(dex_cache.Get() != nullptr);
   Thread::PoisonObjectPointersIfDebug();
@@ -7573,7 +7573,7 @@
 }
 
 mirror::String* ClassLinker::LookupString(const DexFile& dex_file,
-                                          uint32_t string_idx,
+                                          dex::StringIndex string_idx,
                                           Handle<mirror::DexCache> dex_cache) {
   DCHECK(dex_cache.Get() != nullptr);
   ObjPtr<mirror::String> resolved = dex_cache->GetResolvedString(string_idx);
@@ -7582,7 +7582,8 @@
   }
   uint32_t utf16_length;
   const char* utf8_data = dex_file.StringDataAndUtf16LengthByIdx(string_idx, &utf16_length);
-  ObjPtr<mirror::String> string = intern_table_->LookupStrong(Thread::Current(), utf16_length, utf8_data);
+  ObjPtr<mirror::String> string =
+      intern_table_->LookupStrong(Thread::Current(), utf16_length, utf8_data);
   if (string != nullptr) {
     dex_cache->SetResolvedString(string_idx, string);
   }