Fix check for empty type

src/typing.cc

 // Copyright 2013 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 "typing.h"
 
 #include "frames.h"
 #include "frames-inl.h"
 #include "parser.h"  // for CompileTimeValue; TODO(rossberg): should move
 #include "scopes.h"
@@ skipping 657 matching lines @@
       // is no 'positive Smi' type for the lower bound, we use the smallest
       // union of Smi and Unsigned32 as upper bound instead.
       NarrowType(expr, Bounds(Type::SignedSmall(zone()), Type::Number(zone())));
       break;
     case Token::ADD: {
       RECURSE(Visit(expr->left()));
       RECURSE(Visit(expr->right()));
       Bounds l = expr->left()->bounds();
       Bounds r = expr->right()->bounds();
       Type* lower =
-          l.lower->Is(Type::None()) || r.lower->Is(Type::None()) ?
+          !l.lower->IsInhabited() || !r.lower->IsInhabited() ?
               Type::None(zone()) :
           l.lower->Is(Type::String()) || r.lower->Is(Type::String()) ?
               Type::String(zone()) :
           l.lower->Is(Type::Number()) && r.lower->Is(Type::Number()) ?
               Type::SignedSmall(zone()) : Type::None(zone());
       Type* upper =
           l.upper->Is(Type::String()) || r.upper->Is(Type::String()) ?
               Type::String(zone()) :
           l.upper->Is(Type::Number()) && r.upper->Is(Type::Number()) ?
               Type::Number(zone()) : Type::NumberOrString(zone());
@@ skipping 84 matching lines @@
 void AstTyper::VisitModuleUrl(ModuleUrl* module) {
 }
 
 
 void AstTyper::VisitModuleStatement(ModuleStatement* stmt) {
   RECURSE(Visit(stmt->body()));
 }
 
 
 } }  // namespace v8::internal