Test for wrong arguments object materialization.

test/mjsunit/regress/regress-3985.js

+// Copyright 2015 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
+
+var shouldThrow = false;
+
+function h() {
+  try {  // Prevent inlining in Crankshaft.
+  } catch(e) { }
+  var res = g.arguments[0].x;
+  if (shouldThrow) {
+    throw res;
+  }
+  return res;
+}
+
+function g(o) { h(); }
+
+function f1() {
+  var o = { x : 1 };
+  g(o);
+  return o.x;
+}
+
+function f2() {
+  var o = { x : 2 };
+  g(o);
+  return o.x;
+}
+
+f1();
+f2();
+f1();
+f2();
+%OptimizeFunctionOnNextCall(f1);
+%OptimizeFunctionOnNextCall(f2);
+shouldThrow = true;
+try { f1(); } catch(e) {
+  assertEquals(e, 1);
+}
+try { f2(); } catch(e) {
+  assertEquals(e, 2);
+}