Remove unused code from DuplicateFinder.

src/parsing/parser.cc

Index: src/parsing/parser.cc
diff --git a/src/parsing/parser.cc b/src/parsing/parser.cc
index 0c69c92d1ef1ccf8bbb4ef3c06c2d66735566d7a..e3c6a405803a8c69aff42da6e143e6aebaa631af 100644
--- a/src/parsing/parser.cc
+++ b/src/parsing/parser.cc
@@ -3168,7 +3168,7 @@ ZoneList<Statement*>* Parser::ParseFunction(
 
   FunctionState function_state(&function_state_, &scope_state_, function_scope);
 
-  DuplicateFinder duplicate_finder(scanner()->unicode_cache());
+  DuplicateFinder duplicate_finder;
   ExpressionClassifier formals_classifier(this, &duplicate_finder);
 
   if (IsGeneratorFunction(kind)) PrepareGeneratorVariables(&function_state);