Revert of [turbofan] Optimize loads from the global object in JSTypeFeedbackSpecializer.

test/mjsunit/compiler/global-var-delete.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
-
-function test(expected, f) {
-  assertEquals(expected, f());
-  assertEquals(expected, f());
-  %OptimizeFunctionOnNextCall(f);
-  assertEquals(expected, f());
-  assertEquals(expected, f());
-}
-
-function testThrows(f) {
-  assertThrows(f);
-  assertThrows(f);
-  %OptimizeFunctionOnNextCall(f);
-  assertThrows(f);
-  assertThrows(f);
-}
-
-// --- Constant case.
-var a = 11;
-
-function f1() { return a; }
-test(11, f1);
-
-delete a;
-
-test(11, f1);
-
-
-// --- SMI case.
-
-var b = 11;
-b = 12;
-b = 13;
-
-function f2() { return b; }
-test(13, f2);
-
-delete b;
-
-test(13, f2);
-
-
-// --- double case.
-
-var c = 11;
-c = 12.25;
-c = 13.25;
-
-function f3() { return c; }
-test(13.25, f3);
-
-delete c;
-
-test(13.25, f3);
-
-
-// --- tagged case.
-
-var d = 11;
-d = 12.25;
-d = "hello";
-
-function f4() { return d; }
-test("hello", f4);
-
-delete d;
-
-test("hello", f4);