More accurately record an end position for default parameters in arrows

test/mjsunit/regress/regress-4908.js

Index: test/mjsunit/regress/regress-4908.js
diff --git a/test/message/new-target-escaped.js b/test/mjsunit/regress/regress-4908.js
similarity index 68%
copy from test/message/new-target-escaped.js
copy to test/mjsunit/regress/regress-4908.js
index f8398bebd4dda6d8568b3f80cbc85ed2c6d6710e..ec618b32c54559253d0247bb050fecb4d60f15f3 100644
--- a/test/message/new-target-escaped.js
+++ b/test/mjsunit/regress/regress-4908.js
@@ -2,9 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-//
+// Flags: --always-opt --no-lazy
 
-function f() {
-  return new.t\u0061rget;
-}
-var o = new f();
+(function() { ((s = 17, y = s) => s)() })();