Make 'name' property on functions configurable.

test/mjsunit/regress/regress-1530.js

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 44 matching lines @@
 // Verify that the previous redefinition didn't screw up callbacks and
 // the internal value still gets updated.
 var z = { foo: 'other' };
 f.prototype = z;
 assertSame(f.prototype, z);
 assertSame(f.prototype.foo, 'other');
 assertSame(new f().foo, 'other');
 assertSame(Object.getPrototypeOf(new f()), z);
 assertSame(Object.getOwnPropertyDescriptor(f, 'prototype').value, z);
 
-// Verify that non-writability of other properties is respected.
-assertThrows("Object.defineProperty(f, 'name', { value: {} })");
+// Verify that non-configurability of other properties is respected, but
+// non-writability is ignored by Object.defineProperty().
+assertDoesNotThrow("Object.defineProperty(f, 'name', { value: {} })");
 assertThrows("Object.defineProperty(f, 'length', { value: {} })");
 assertThrows("Object.defineProperty(f, 'caller', { value: {} })");
 assertThrows("Object.defineProperty(f, 'arguments', { value: {} })");