Correctly handle clearing of deprecated field types.

test/mjsunit/regress/regress-4027.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 --expose-gc
+
+function Inner() {
+  this.inner_name = "inner";
+}
+
+function Boom() {
+  this.boom = "boom";
+}
+
+function Outer() {
+  this.outer_name = "outer";
+}
+
+function SetInner(inner, value) {
+  inner.prop = value;
+}
+
+function SetOuter(outer, value) {
+  outer.inner = value;
+}
+
+var inner1 = new Inner();
+var inner2 = new Inner();
+
+SetInner(inner1, 10);
+SetInner(inner2, 10);
+
+var outer1 = new Outer();
+var outer2 = new Outer();
+var outer3 = new Outer();
+
+SetOuter(outer1, inner1);
+SetOuter(outer1, inner1);
+SetOuter(outer1, inner1);
+
+SetOuter(outer2, inner2);
+SetOuter(outer2, inner2);
+SetOuter(outer2, inner2);
+
+SetOuter(outer3, inner2);
+SetOuter(outer3, inner2);
+SetOuter(outer3, inner2);
+
+
+SetInner(inner2, 6.5);
+
+outer1 = null;
+inner1 = null;
+
+for (var i = 0; i < 3; i++) gc();

[Jakob Kummerow, 2015/04/15 09:25:16]

Isn't a single GC sufficient?

[ulan, 2015/04/15 09:31:44]

Done. Yes, assert triggers with single GC.

+
+var boom = new Boom();
+SetOuter(outer2, boom);
+
+for (var i = 0; i < 3; i++) gc();