[turbofan] Handle impossible types (Type::None()) in the backend.

src/compiler/machine-operator.cc

Index: src/compiler/machine-operator.cc
diff --git a/src/compiler/machine-operator.cc b/src/compiler/machine-operator.cc
index 3203e2a3abdfaefff4fdecfdff56ba347ca96960..b783f730765970c2fab2a9267da0783f2815dd3f 100644
--- a/src/compiler/machine-operator.cc
+++ b/src/compiler/machine-operator.cc
@@ -135,6 +135,12 @@ MachineRepresentation AtomicStoreRepresentationOf(Operator const* op) {
   V(ChangeInt32ToInt64, Operator::kNoProperties, 1, 0, 1)                    \
   V(ChangeUint32ToFloat64, Operator::kNoProperties, 1, 0, 1)                 \
   V(ChangeUint32ToUint64, Operator::kNoProperties, 1, 0, 1)                  \
+  V(ImpossibleToWord32, Operator::kNoProperties, 1, 0, 1)                    \
+  V(ImpossibleToWord64, Operator::kNoProperties, 1, 0, 1)                    \
+  V(ImpossibleToFloat32, Operator::kNoProperties, 1, 0, 1)                   \
+  V(ImpossibleToFloat64, Operator::kNoProperties, 1, 0, 1)                   \
+  V(ImpossibleToTagged, Operator::kNoProperties, 1, 0, 1)                    \
+  V(ImpossibleToBit, Operator::kNoProperties, 1, 0, 1)                       \
   V(TruncateFloat64ToFloat32, Operator::kNoProperties, 1, 0, 1)              \
   V(TruncateInt64ToInt32, Operator::kNoProperties, 1, 0, 1)                  \
   V(BitcastFloat32ToInt32, Operator::kNoProperties, 1, 0, 1)                 \