[turbofan] Separate representation type operations from the semantic types.

src/hydrogen-types.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/hydrogen-types.h"
 
 #include "src/ostreams.h"
 #include "src/types-inl.h"
 
 
 namespace v8 {
 namespace internal {
 
 // static
 template <class T>
 HType HType::FromType(typename T::TypeHandle type) {
   if (T::Any()->Is(type)) return HType::Any();
-  if (type->Is(T::None())) return HType::None();
+  if (!type->IsInhabited()) return HType::None();
   if (type->Is(T::SignedSmall())) return HType::Smi();
   if (type->Is(T::Number())) return HType::TaggedNumber();
   if (type->Is(T::Null())) return HType::Null();
   if (type->Is(T::String())) return HType::String();
   if (type->Is(T::Boolean())) return HType::Boolean();
   if (type->Is(T::Undefined())) return HType::Undefined();
   if (type->Is(T::Array())) return HType::JSArray();
   if (type->Is(T::Object())) return HType::JSObject();
   if (type->Is(T::Receiver())) return HType::JSReceiver();
   return HType::Tagged();
@@ skipping 36 matching lines @@
   case HType::k##Name:          \
     return os << #Name;
     HTYPE_LIST(DEFINE_CASE)
 #undef DEFINE_CASE
   }
   UNREACHABLE();
   return os;
 }
 
 } }  // namespace v8::internal