Introduce FeedbackVectorSlot type - better than int.

src/full-codegen.cc

 // Copyright 2012 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/v8.h"
 
 #include "src/code-factory.h"
 #include "src/codegen.h"
 #include "src/compiler.h"
 #include "src/debug.h"
@@ skipping 347 matching lines @@
   __ dd(length);
   for (unsigned i = 0; i < length; ++i) {
     __ dd(back_edges_[i].id.ToInt());
     __ dd(back_edges_[i].pc);
     __ dd(back_edges_[i].loop_depth);
   }
   return offset;
 }
 
 
-void FullCodeGenerator::EnsureSlotContainsAllocationSite(int slot) {
+void FullCodeGenerator::EnsureSlotContainsAllocationSite(
+    FeedbackVectorSlot slot) {
   Handle<FixedArray> vector = FeedbackVector();
-  if (!vector->get(slot)->IsAllocationSite()) {
+  if (!vector->get(slot.ToInt())->IsAllocationSite()) {
     Handle<AllocationSite> allocation_site =
         isolate()->factory()->NewAllocationSite();
-    vector->set(slot, *allocation_site);
+    vector->set(slot.ToInt(), *allocation_site);
   }
 }
 
 
 void FullCodeGenerator::PopulateDeoptimizationData(Handle<Code> code) {
   // Fill in the deoptimization information.
   DCHECK(info_->HasDeoptimizationSupport() || bailout_entries_.is_empty());
   if (!info_->HasDeoptimizationSupport()) return;
   int length = bailout_entries_.length();
   Handle<DeoptimizationOutputData> data =
@@ skipping 1348 matching lines @@
   }
   return true;
 }
 #endif  // DEBUG
 
 
 #undef __
 
 
 } }  // namespace v8::internal