More accurately record an end position for default parameters in arrows

src/parsing/parser.h

Index: src/parsing/parser.h
diff --git a/src/parsing/parser.h b/src/parsing/parser.h
index 6285c0c6789d9d98c3b2c7f151c7b41e4b494922..f971cf7661ceae42c3007c19300e11a1d9c7cbf2 100644
--- a/src/parsing/parser.h
+++ b/src/parsing/parser.h
@@ -541,8 +541,7 @@ class ParserTraits {
       Scope* scope, const ParserFormalParameters::Parameter& parameter,
       Type::ExpressionClassifier* classifier);
   void ParseArrowFunctionFormalParameters(ParserFormalParameters* parameters,
-                                          Expression* params,
-                                          const Scanner::Location& params_loc,
+                                          Expression* params, int end_pos,
                                           bool* ok);
   void ParseArrowFunctionFormalParameterList(
       ParserFormalParameters* parameters, Expression* params,