Fix stale IC::receiver_map_ after prototype fastification

test/mjsunit/regress/regress-crbug-618845.js

Index: test/mjsunit/regress/regress-crbug-618845.js
diff --git a/test/mjsunit/regress/regress-crbug-618845.js b/test/mjsunit/regress/regress-crbug-618845.js
new file mode 100644
index 0000000000000000000000000000000000000000..ea3baba0bb927ecbd5bae85295eea1e490c66e14
--- /dev/null
+++ b/test/mjsunit/regress/regress-crbug-618845.js
@@ -0,0 +1,16 @@
+// 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 Foo() {}
+Object.defineProperty(Foo.prototype, "name",
+                      {get: function() { return "FooName"; }});
+
+function ic(f) {
+  return f.prototype.name;
+}
+
+assertEquals("FooName", ic(Foo));
+assertEquals("FooName", ic(Foo));  // Don't crash, don't time out.