[turbofan] Use range types to type and lower arithmetic ops.

src/types.h

 // 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.
 
 #ifndef V8_TYPES_H_
 #define V8_TYPES_H_
 
 #include "src/conversions.h"
 #include "src/factory.h"
 #include "src/handles.h"
@@ skipping 769 matching lines @@
 
 template<class Config>
 class TypeImpl<Config>::RangeType : public StructuralType {
  public:
   int BitsetLub() { return this->Get(0)->AsBitset(); }
   i::Handle<i::Object> Min() { return this->template GetValue<i::Object>(1); }
   i::Handle<i::Object> Max() { return this->template GetValue<i::Object>(2); }
 
   static RangeHandle New(
       i::Handle<i::Object> min, i::Handle<i::Object> max, Region* region) {
+    DCHECK(IsInteger(min->Number()) && IsInteger(max->Number()));
     DCHECK(min->Number() <= max->Number());
     RangeHandle type = Config::template cast<RangeType>(
         StructuralType::New(StructuralType::kRangeTag, 3, region));
     type->Set(0, BitsetType::New(
         BitsetType::Lub(min->Number(), max->Number()), region));
     type->SetValue(1, min);
     type->SetValue(2, max);
     return type;
   }
 
@@ skipping 256 matching lines @@
   bool Narrows(BoundsImpl that) {
     return that.lower->Is(this->lower) && this->upper->Is(that.upper);
   }
 };
 
 typedef BoundsImpl<ZoneTypeConfig> Bounds;
 
 } }  // namespace v8::internal
 
 #endif  // V8_TYPES_H_