Remove more dead code after Object.observe removal

test/mjsunit/regress/regress-1240.js

Index: test/mjsunit/regress/regress-1240.js
diff --git a/test/mjsunit/regress/regress-1240.js b/test/mjsunit/regress/regress-1240.js
index 1a0bf2edb631f6a5cc83aa572ef0ff969ba0a03f..57d72b0a5a1c7a5dc4afb6b8f28f1dc30a5ec13f 100644
--- a/test/mjsunit/regress/regress-1240.js
+++ b/test/mjsunit/regress/regress-1240.js
@@ -33,7 +33,9 @@ var a = {};
 Object.defineProperty(a, 'b',
                       { get: function () { return 42; }, configurable: false });
 // Do not allow us to redefine b on a.
-a.__defineGetter__('b', function _b(){ return 'foo'; });
+try {
+  a.__defineGetter__('b', function _b(){ return 'foo'; });
+} catch (e) {}
 assertEquals(42, a.b);
 var desc = Object.getOwnPropertyDescriptor(a, 'b');
 assertFalse(desc.configurable);