[turbofan] Broaden checkpoint elimination on returns.

test/mjsunit/regress/regress-crbug-624747.js

Index: test/mjsunit/regress/regress-crbug-624747.js
diff --git a/test/mjsunit/regress/regress-crbug-624747.js b/test/mjsunit/regress/regress-crbug-624747.js
new file mode 100644
index 0000000000000000000000000000000000000000..7927263f8ec17000c486c55dc9634a6525d62e61
--- /dev/null
+++ b/test/mjsunit/regress/regress-crbug-624747.js
@@ -0,0 +1,22 @@
+// 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 --es-staging
+
+"use strict";
+
+function bar() {
+  try {
+    unref;
+  } catch (e) {
+    return (1 instanceof TypeError) && unref();  // Call in tail position!
+  }
+}
+
+function foo() {
+  return bar();  // Call in tail position!
+}
+
+%OptimizeFunctionOnNextCall(foo);
+foo();