Improving error messages when adding properties to non JSObject receiver in

test/mjsunit/harmony/super.js

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Flags: --allow-natives-syntax
 // Flags: --harmony-spread-calls --harmony-destructuring
 // Flags: --harmony-rest-parameters --harmony-sloppy
 
 (function TestSuperNamedLoads() {
   function Base() { }
@@ skipping 1058 matching lines @@
       'use strict';
       var ex;
       assertEquals(42, this.ownReadOnly);
       try {
         super.ownReadOnly = 55;
       } catch (e) {
         ex = e;
       }
       assertInstanceof(ex, TypeError);
       assertEquals(
-          "Cannot assign to read only property 'ownReadOnly' of #<Base>",
+          "Cannot assign to read only property 'ownReadOnly' of object '#<Base>'",
           ex.message);
       assertEquals(42, this.ownReadOnly);
 
       ex = null;
       assertEquals(15, this.ownReadonlyAccessor);
       try {
         super.ownReadonlyAccessor = 25;
       } catch (e) {
         ex = e;
       }
@@ skipping 226 matching lines @@
       var ex;
       assertEquals(42, this[ownReadOnly]);
       try {
         super[ownReadOnly] = 55;
       } catch (e) {
         ex = e;
       }
       assertInstanceof(ex, TypeError);
       assertEquals(
           "Cannot assign to read only property '" + ownReadOnly +
-              "' of #<Base>",
+              "' of object '#<Base>'",
           ex.message);
       assertEquals(42, this[ownReadOnly]);
 
       ex = null;
       assertEquals(15, this[ownReadonlyAccessor]);
       try {
         super[ownReadonlyAccessor] = 25;
       } catch (e) {
         ex = e;
       }
@@ skipping 913 matching lines @@
   }
   class Derived extends Base {
     constructor(x) {
       let r = (() => super(...[x]))();
       assertEquals(this, r);
     }
   }
   let d = new Derived(42);
   assertSame(42, d.x);
 })();