[turbofan] Fix ObjectCreate's side effect annotation.

Bug: chromium:888923
Change-Id: Ifb22cd9b34f53de3cf6e47cd92f3c0abeb10ac79
Reviewed-on: https://chromium-review.googlesource.com/1245763Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Jaroslav Sevcik <jarin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56236}

src/compiler/js-operator.cc

@@ -622,7 +622,7 @@ CompareOperationHint CompareOperationHintOf(const Operator* op) {
   V(CreateKeyValueArray, Operator::kEliminatable, 2, 1)                \
   V(CreatePromise, Operator::kEliminatable, 0, 1)                      \
   V(CreateTypedArray, Operator::kNoProperties, 5, 1)                   \
-  V(CreateObject, Operator::kNoWrite, 1, 1)                            \
+  V(CreateObject, Operator::kNoProperties, 1, 1)                       \
   V(ObjectIsArray, Operator::kNoProperties, 1, 1)                      \
   V(HasProperty, Operator::kNoProperties, 2, 1)                        \
   V(HasInPrototypeChain, Operator::kNoProperties, 2, 1)                \

test/mjsunit/compiler/regress-888923.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
+
+(function() {
+  function f(o) {
+    o.x;
+    Object.create(o);
+    return o.y.a;
+  }
+
+  f({ x : 0, y : { a : 1 } });
+  f({ x : 0, y : { a : 2 } });
+  %OptimizeFunctionOnNextCall(f);
+  assertEquals(3, f({ x : 0, y : { a : 3 } }));
+})();
+
+(function() {
+  function f(o) {
+    let a = o.y;
+    Object.create(o);
+    return o.x + a;
+  }
+
+  f({ x : 42, y : 21 });
+  f({ x : 42, y : 21 });
+  %OptimizeFunctionOnNextCall(f);
+  assertEquals(63, f({ x : 42, y : 21 }));
+})();