[x86] Fix InstructionSelector::SupportedMachineOperatorFlags().

src/compiler/x64/instruction-selector-x64.cc

 // Copyright 2014 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.
 
 #include <algorithm>
 
 #include "src/compiler/instruction-selector-impl.h"
 #include "src/compiler/node-matchers.h"
 #include "src/compiler/node-properties.h"
 
@@ skipping 1356 matching lines @@
 
 void InstructionSelector::VisitFloat64LessThanOrEqual(Node* node) {
   FlagsContinuation cont(kUnsignedGreaterThanOrEqual, node);
   VisitFloat64Compare(this, node, &cont);
 }
 
 
 // static
 MachineOperatorBuilder::Flags
 InstructionSelector::SupportedMachineOperatorFlags() {
+  MachineOperatorBuilder::Flags flags =
+      MachineOperatorBuilder::kWord32ShiftIsSafe;
   if (CpuFeatures::IsSupported(SSE4_1)) {
-    return MachineOperatorBuilder::kFloat64Floor |
-           MachineOperatorBuilder::kFloat64Ceil |
-           MachineOperatorBuilder::kFloat64RoundTruncate |
-           MachineOperatorBuilder::kWord32ShiftIsSafe;
+    flags |= MachineOperatorBuilder::kFloat64Floor |
+             MachineOperatorBuilder::kFloat64Ceil |
+             MachineOperatorBuilder::kFloat64RoundTruncate;
   }
-  return MachineOperatorBuilder::kNoFlags;
+  return flags;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8