ART: Fix old warnings

Fix Wundefined-var-template warnings.

Partially reverts commit df53be273509dd43725870fb20a2c7d71f7fbfd3.

Bug: 28149048
Bug: 29823425
Test: m
Test: m test-art-host
Change-Id: Ib077312558f9e2f784859861c000fbac8375b3f5
diff --git a/runtime/mirror/class.cc b/runtime/mirror/class.cc
index 06ee3d3..e4b5320 100644
--- a/runtime/mirror/class.cc
+++ b/runtime/mirror/class.cc
@@ -1143,9 +1143,7 @@
 dex::TypeIndex Class::FindTypeIndexInOtherDexFile(const DexFile& dex_file) {
   std::string temp;
   const DexFile::TypeId* type_id = dex_file.FindTypeId(GetDescriptor(&temp));
-  return (type_id == nullptr)
-      ? dex::TypeIndex(DexFile::kDexNoIndex)
-      : dex_file.GetIndexForTypeId(*type_id);
+  return (type_id == nullptr) ? dex::TypeIndex() : dex_file.GetIndexForTypeId(*type_id);
 }
 
 template <PointerSize kPointerSize, bool kTransactionActive>