[turbofan] Insert dummy values when changing from None type.

test/mjsunit/compiler/regress-638132.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(x, y) {
+  return x | y;
+}
+
+function f(b) {
+  if (b) {
+    var s = g("a", "b") && true;
+    return s;
+  }
+}
+
+// Prime function g with Smi feedback.
+g(1, 2);
+g(1, 2);
+
+f(0);
+f(0);
+%OptimizeFunctionOnNextCall(f);
+// Compile inlined function g with string inputs but Smi feedback.
+f(1);