Remove unnecessary language_mode arg from Parser::DefaultConstructor

src/parsing/parser.h

Index: src/parsing/parser.h
diff --git a/src/parsing/parser.h b/src/parsing/parser.h
index 7796797b011e08e65f8eacaab48cac27332a02f8..6c77856303e53b3e38561d8ddf8f15cabfdc6615 100644
--- a/src/parsing/parser.h
+++ b/src/parsing/parser.h
@@ -518,8 +518,7 @@ class V8_EXPORT_PRIVATE Parser : public NON_EXPORTED_BASE(ParserBase<Parser>) {
 
   // Factory methods.
   FunctionLiteral* DefaultConstructor(const AstRawString* name, bool call_super,
-                                      int pos, int end_pos,
-                                      LanguageMode language_mode);
+                                      int pos, int end_pos);
 
   // Skip over a lazy function, either using cached data if we have it, or
   // by parsing the function with PreParser. Consumes the ending }.