[turbofan] Teach escape analysis about ObjectIsNaN.

test/mjsunit/regress/regress-crbug-698607.js

Index: test/mjsunit/regress/regress-crbug-698607.js
diff --git a/test/mjsunit/regress/regress-crbug-698607.js b/test/mjsunit/regress/regress-crbug-698607.js
new file mode 100644
index 0000000000000000000000000000000000000000..c9df4257f14fe1fcecb4e79e4aae7a591ff3461b
--- /dev/null
+++ b/test/mjsunit/regress/regress-crbug-698607.js
@@ -0,0 +1,22 @@
+// Copyright 2017 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 assertSame(expected, found) {
+  if (found === expected) {
+  } else if ((expected !== expected) && (found !== found)) {
+  }
+}
+
+function foo() {
+  var x = {var: 0.5};
+  assertSame(x, x.val);
+  return () => x;
+}
+
+foo(1);
+foo(1);
+%OptimizeFunctionOnNextCall(foo);
+foo(1);