Fix 'typeof null' canonicalization in crankshaft

test/mjsunit/regress/regress-opt-typeof-null.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
 
-function g() { if (false) throw 0; }
-function f() { g(); }
+function f() {
+  return typeof null === "object";
+};
 
-f();
-f();
 %OptimizeFunctionOnNextCall(f);
-f();
+assertTrue(f());