[turbofan] Prevent storing signalling NaNs into holey double arrays.

src/compiler/ia32/instruction-selector-ia32.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 "src/base/adapters.h"
 #include "src/compiler/instruction-selector-impl.h"
 #include "src/compiler/node-matchers.h"
 #include "src/compiler/node-properties.h"
 
 namespace v8 {
@@ skipping 1582 matching lines @@
 
 
 void InstructionSelector::VisitFloat64InsertHighWord32(Node* node) {
   IA32OperandGenerator g(this);
   Node* left = node->InputAt(0);
   Node* right = node->InputAt(1);
   Emit(kSSEFloat64InsertHighWord32, g.DefineSameAsFirst(node),
        g.UseRegister(left), g.Use(right));
 }
 
+void InstructionSelector::VisitFloat64SilenceNaN(Node* node) {
+  IA32OperandGenerator g(this);
+  Emit(kSSEFloat64SilenceNaN, g.DefineSameAsFirst(node),
+       g.UseRegister(node->InputAt(0)));
+}
+
 void InstructionSelector::VisitAtomicLoad(Node* node) {
   LoadRepresentation load_rep = LoadRepresentationOf(node->op());
   DCHECK(load_rep.representation() == MachineRepresentation::kWord8 ||
          load_rep.representation() == MachineRepresentation::kWord16 ||
          load_rep.representation() == MachineRepresentation::kWord32);
   USE(load_rep);
   VisitLoad(node);
 }
 
 void InstructionSelector::VisitAtomicStore(Node* node) {
@@ skipping 63 matching lines @@
 // static
 MachineOperatorBuilder::AlignmentRequirements
 InstructionSelector::AlignmentRequirements() {
   return MachineOperatorBuilder::AlignmentRequirements::
       FullUnalignedAccessSupport();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8