Revert of [turbofan] Optimize string "length" property access based on types.

test/mjsunit/compiler/string-length.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
-
-assertEquals(0, "".length);
-assertEquals(1, "a".length);
-assertEquals(2, ("a" + "b").length);
-
-function id(x) { return x; }
-
-function f1(x) {
-  return x.length;
-}
-assertEquals(0, f1(""));
-assertEquals(1, f1("a"));
-%OptimizeFunctionOnNextCall(f1);
-assertEquals(2, f1("a" + "b"));
-assertEquals(3, f1(id("a") + id("b" + id("c"))))
-
-function f2(x, y, z) {
-  x = x ? "" + y : "" + z;
-  return x.length;
-}
-assertEquals(0, f2(true, "", "a"));
-assertEquals(1, f2(false, "", "a"));
-%OptimizeFunctionOnNextCall(f2);
-assertEquals(0, f2(true, "", "a"));
-assertEquals(1, f2(false, "", "a"));
-assertEquals(3, f2(true, id("a") + id("b" + id("c")), ""));