Remove unused code from DuplicateFinder.

src/parsing/parser-base.h

Index: src/parsing/parser-base.h
diff --git a/src/parsing/parser-base.h b/src/parsing/parser-base.h
index ae917b82f4ecb7dbe07b057b4a8d7d1204aee8dc..5bbdd8e9302a460f24760c9853cb7e9ffe20eba6 100644
--- a/src/parsing/parser-base.h
+++ b/src/parsing/parser-base.h
@@ -1610,7 +1610,7 @@ ParserBase<Impl>::ParseAndClassifyIdentifier(bool* ok) {
     }
 
     if (classifier()->duplicate_finder() != nullptr &&
-        scanner()->FindSymbol(classifier()->duplicate_finder(), 1) != 0) {
+        scanner()->FindSymbol(classifier()->duplicate_finder())) {
       classifier()->RecordDuplicateFormalParameterError(scanner()->location());
     }
     return name;
@@ -2374,7 +2374,7 @@ ParserBase<Impl>::ParseObjectPropertyDefinition(ObjectLiteralChecker* checker,
       DCHECK(!*is_computed_name);
 
       if (classifier()->duplicate_finder() != nullptr &&
-          scanner()->FindSymbol(classifier()->duplicate_finder(), 1) != 0) {
+          scanner()->FindSymbol(classifier()->duplicate_finder())) {
         classifier()->RecordDuplicateFormalParameterError(
             scanner()->location());
       }