[crankshaft] Don't bailout on uninitialized access to arguments object.

test/mjsunit/regress/regress-5790.js

Index: test/mjsunit/regress/regress-5790.js
diff --git a/test/mjsunit/regress/regress-5790.js b/test/mjsunit/regress/regress-5790.js
new file mode 100644
index 0000000000000000000000000000000000000000..7790db5ea9c72cc741816a543e171119f4cba8c4
--- /dev/null
+++ b/test/mjsunit/regress/regress-5790.js
@@ -0,0 +1,20 @@
+// 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 foo(a) {
+  "use strict";
+  if (a) return arguments[1];
+}
+
+foo(false);
+foo(false);
+%OptimizeFunctionOnNextCall(foo);
+foo(true, 1);
+foo(true, 1);
+%OptimizeFunctionOnNextCall(foo);
+foo(false);
+foo(true, 1);
+assertOptimized(foo);