[turbofan] Add support for storing to double fields.

src/compiler/instruction-selector.cc

Index: src/compiler/instruction-selector.cc
diff --git a/src/compiler/instruction-selector.cc b/src/compiler/instruction-selector.cc
index 0569ab70844756d4e0a675cade887efabc2cc751..c7d702d679c00ecd110223a59692fed162ea10c5 100644
--- a/src/compiler/instruction-selector.cc
+++ b/src/compiler/instruction-selector.cc
@@ -556,6 +556,8 @@ void InstructionSelector::VisitNode(Node* node) {
       return MarkAsReference(node), VisitIfException(node);
     case IrOpcode::kFinishRegion:
       return MarkAsReference(node), VisitFinishRegion(node);
+    case IrOpcode::kGuard:
+      return MarkAsReference(node), VisitGuard(node);
     case IrOpcode::kParameter: {
       MachineType type =
           linkage()->GetParameterType(ParameterIndexOf(node->op()));
@@ -941,6 +943,13 @@ void InstructionSelector::VisitFinishRegion(Node* node) {
 }
 
 
+void InstructionSelector::VisitGuard(Node* node) {
+  OperandGenerator g(this);
+  Node* value = node->InputAt(0);
+  Emit(kArchNop, g.DefineSameAsFirst(node), g.Use(value));
+}
+
+
 void InstructionSelector::VisitParameter(Node* node) {
   OperandGenerator g(this);
   int index = ParameterIndexOf(node->op());