[turbofan] Add missing check in JSCallReducer

Bug: chromium:843543
Change-Id: I709c4be330e7d45e597b3ca4ae9db8a960b07bbc
Reviewed-on: https://chromium-review.googlesource.com/1061463Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
Cr-Commit-Position: refs/heads/master@{#53216}

src/compiler/js-call-reducer.cc

@@ -2528,6 +2528,7 @@ Reduction JSCallReducer::ReduceArrayIndexOfIncludes(
   if (!NodeProperties::GetMapWitness(node).ToHandle(&receiver_map))
     return NoChange();
 
+  if (receiver_map->instance_type() != JS_ARRAY_TYPE) return NoChange();
   if (!IsFastElementsKind(receiver_map->elements_kind())) return NoChange();
 
   Callable const callable =

test/mjsunit/regress/regress-843543.js

+// Copyright 2018 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
+
+const o = {x:9};
+o.__proto__ = Array.prototype;
+
+function foo(o) {
+  return o.indexOf(undefined);
+}
+
+assertEquals(-1, foo(o));
+assertEquals(-1, foo(o));
+%OptimizeFunctionOnNextCall(foo);
+assertEquals(-1, foo(o));