Implement optional turbofan UnalignedLoad and UnalignedStore operators

src/compiler/machine-operator.h

Index: src/compiler/machine-operator.h
diff --git a/src/compiler/machine-operator.h b/src/compiler/machine-operator.h
index fda941743dee9793177537497c00859911b7e442..37906d8baccdb0f2cd19c23c732e228eaddae0c4 100644
--- a/src/compiler/machine-operator.h
+++ b/src/compiler/machine-operator.h
@@ -90,6 +90,15 @@ std::ostream& operator<<(std::ostream&, StoreRepresentation);
 
 StoreRepresentation const& StoreRepresentationOf(Operator const*);
 
+typedef MachineType UnalignedLoadRepresentation;
+
+UnalignedLoadRepresentation UnalignedLoadRepresentationOf(Operator const*);
+
+// An UnalignedStore needs a MachineType.
+typedef MachineRepresentation UnalignedStoreRepresentation;
+
+UnalignedStoreRepresentation const& UnalignedStoreRepresentationOf(
+    Operator const*);
 
 // A CheckedLoad needs a MachineType.
 typedef MachineType CheckedLoadRepresentation;
@@ -315,6 +324,12 @@ class MachineOperatorBuilder final : public ZoneObject {
   // store [base + index], value
   const Operator* Store(StoreRepresentation rep);
 
+  // unaligned load [base + index]
+  const Operator* UnalignedLoad(UnalignedLoadRepresentation rep);
+
+  // unaligned store [base + index], value
+  const Operator* UnalignedStore(UnalignedStoreRepresentation rep);
+
   const Operator* StackSlot(MachineRepresentation rep);
 
   // Access to the machine stack.