[turbofan] Teach escape analysis about ConvertTaggedHoleToUndefined.

test/mjsunit/regress/regress-crbug-669451.js

Index: test/mjsunit/regress/regress-crbug-669451.js
diff --git a/test/mjsunit/regress/regress-crbug-669451.js b/test/mjsunit/regress/regress-crbug-669451.js
new file mode 100644
index 0000000000000000000000000000000000000000..0bbc1c1a968e9281e745b2668306403be44b7af4
--- /dev/null
+++ b/test/mjsunit/regress/regress-crbug-669451.js
@@ -0,0 +1,15 @@
+// Copyright 2016 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
+
+function foo() {
+  var a = [,];
+  a[0] = {}
+  a[0].toString = FAIL;
+}
+try { foo(); } catch (e) {}
+try { foo(); } catch (e) {}
+%OptimizeFunctionOnNextCall(foo);
+try { foo(); } catch (e) {}