Fix Win64 size_t/int conversion after b3f2277ea42a.

src/compiler/register-allocator.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/register-allocator.h"
 
 #include "src/compiler/linkage.h"
 #include "src/hydrogen.h"
 #include "src/string-stream.h"
 
@@ skipping 515 matching lines @@
 BitVector* RegisterAllocator::ComputeLiveOut(const InstructionBlock* block) {
   // Compute live out for the given block, except not including backward
   // successor edges.
   BitVector* live_out =
       new (zone()) BitVector(code()->VirtualRegisterCount(), zone());
 
   // Process all successor blocks.
   for (auto succ : block->successors()) {
     // Add values live on entry to the successor. Note the successor's
     // live_in will not be computed yet for backwards edges.
-    BitVector* live_in = live_in_sets_[succ.ToSize()];
+    BitVector* live_in = live_in_sets_[static_cast<int>(succ.ToSize())];
     if (live_in != NULL) live_out->Union(*live_in);
 
     // All phi input operands corresponding to this successor edge are live
     // out from this block.
     const InstructionBlock* successor = code()->InstructionBlockAt(succ);
     size_t index = successor->PredecessorIndexOf(block->rpo_number());
     DCHECK(index < successor->PredecessorCount());
     for (auto phi : successor->phis()) {
       live_out->Add(phi->operands()[index]);
     }
@@ skipping 1666 matching lines @@
                     allocator_zone_start_allocation_size_;
     isolate()->GetTStatistics()->SaveTiming(name(), base::TimeDelta(), size);
   }
 #ifdef DEBUG
   if (allocator_ != NULL) allocator_->Verify();
 #endif
 }
 }
 }
 }  // namespace v8::internal::compiler