Implement optional turbofan UnalignedLoad and UnalignedStore operators

src/compiler/machine-operator-reducer.h

Index: src/compiler/machine-operator-reducer.h
diff --git a/src/compiler/machine-operator-reducer.h b/src/compiler/machine-operator-reducer.h
index 7f8ff1a5fd6bd33a70a653acefdfbdf31e823695..24314fe027358b3f3f054b39d5ae49ab3c844fe5 100644
--- a/src/compiler/machine-operator-reducer.h
+++ b/src/compiler/machine-operator-reducer.h
@@ -72,6 +72,7 @@ class MachineOperatorReducer final : public Reducer {
   Reduction ReduceUint32Mod(Node* node);
   Reduction ReduceTruncateFloat64ToInt32(Node* node);
   Reduction ReduceStore(Node* node);
+  Reduction ReduceUnalignedStore(Node* node);
   Reduction ReduceProjection(size_t index, Node* node);
   Reduction ReduceWord32Shifts(Node* node);
   Reduction ReduceWord32Shl(Node* node);