Implement optional turbofan UnalignedLoad and UnalignedStore operators

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 5fc0f3c134566d61f4f5ebcfea1fd981804e2577..b15a5b5ed55a8f851633964abcfbaf517822ea55 100644
--- a/src/compiler/instruction-selector.cc
+++ b/src/compiler/instruction-selector.cc
@@ -1142,6 +1142,14 @@ void InstructionSelector::VisitNode(Node* node) {
       return VisitLoadFramePointer(node);
     case IrOpcode::kLoadParentFramePointer:
       return VisitLoadParentFramePointer(node);
+    case IrOpcode::kUnalignedLoad: {
+      UnalignedLoadRepresentation type =
+          UnalignedLoadRepresentationOf(node->op());
+      MarkAsRepresentation(type.representation(), node);
+      return VisitUnalignedLoad(node);
+    }
+    case IrOpcode::kUnalignedStore:
+      return VisitUnalignedStore(node);
     case IrOpcode::kCheckedLoad: {
       MachineRepresentation rep =
           CheckedLoadRepresentationOf(node->op()).representation();