[turbofan] Avoid dereferencing empty handle when inlining a tail call.

test/mjsunit/regress/regress-crbug-593697-2.js

 // 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 --harmony-tailcalls
-// TODO(v8:4698), TODO(ishell): support these cases.
-// Flags: --turbo --nostress-opt
 
-try {
-  load("mjsunit/es6/tail-call-megatest.js");
-} catch(e) {
-  load("test/mjsunit/es6/tail-call-megatest.js");
-}
+"use strict";
 
-run_tests(1);
+%SetForceInlineFlag(Math.cos);
+
+var f5 = (function f6(stdlib) {
+  "use asm";
+  var cos = stdlib.Math.cos;
+  function f5() {
+    return cos();
+  }
+  return { f5: f5 };
+})(this, {}).f5();