Introduce FeedbackVectorSlot type - better than int.

src/compiler/js-operator.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/compiler/js-operator.h"
 
 #include <limits>
 
 #include "src/base/lazy-instance.h"
 #include "src/compiler/opcodes.h"
@@ skipping 91 matching lines @@
 
 
 ContextAccess const& ContextAccessOf(Operator const* op) {
   DCHECK(op->opcode() == IrOpcode::kJSLoadContext ||
          op->opcode() == IrOpcode::kJSStoreContext);
   return OpParameter<ContextAccess>(op);
 }
 
 
 bool operator==(VectorSlotPair const& lhs, VectorSlotPair const& rhs) {
-  return lhs.slot() == rhs.slot() && lhs.vector().is_identical_to(rhs.vector());
+  return lhs.slot().ToInt() == rhs.slot().ToInt() &&
+         lhs.vector().is_identical_to(rhs.vector());
 }
 
 
 size_t hash_value(VectorSlotPair const& p) {
   // TODO(mvstanton): include the vector in the hash.
   base::hash<int> h;
-  return h(p.slot());
+  return h(p.slot().ToInt());
 }
 
 
 bool operator==(LoadNamedParameters const& lhs,
                 LoadNamedParameters const& rhs) {
   return lhs.name() == rhs.name() &&
          lhs.contextual_mode() == rhs.contextual_mode() &&
          lhs.feedback() == rhs.feedback();
 }
 
@@ skipping 233 matching lines @@
 const Operator* JSOperatorBuilder::CreateCatchContext(
     const Unique<String>& name) {
   return new (zone()) Operator1<Unique<String>>(IrOpcode::kJSCreateCatchContext,
                                                 Operator::kNoProperties, 1, 1,
                                                 "JSCreateCatchContext", name);
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8