Fix compilation issue on Win64.

src/spaces.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 681 matching lines @@
 
 
 int MemoryAllocator::CodePageGuardStartOffset() {
   // We are guarding code pages: the first OS page after the header
   // will be protected as non-writable.
   return RoundUp(Page::kObjectStartOffset, OS::CommitPageSize());
 }
 
 
 int MemoryAllocator::CodePageGuardSize() {
-  return OS::CommitPageSize();
+  return static_cast<int>(OS::CommitPageSize());
 }
 
 
 int MemoryAllocator::CodePageAreaStartOffset() {
   // We are guarding code pages: the first OS page after the header
   // will be protected as non-writable.
   return CodePageGuardStartOffset() + CodePageGuardSize();
 }
 
 
 int MemoryAllocator::CodePageAreaEndOffset() {
   // We are guarding code pages: the last OS page will be protected as
   // non-writable.
-  return Page::kPageSize - OS::CommitPageSize();
+  return Page::kPageSize - static_cast<int>(OS::CommitPageSize());
 }
 
 
 bool MemoryAllocator::CommitCodePage(VirtualMemory* vm,
                                      Address start,
                                      size_t size) {
   // Commit page header (not executable).
   if (!vm->Commit(start,
                   CodePageGuardStartOffset(),
                   false)) {
@@ skipping 2055 matching lines @@
     object->ShortPrint();
     PrintF("\n");
   }
   printf(" --------------------------------------\n");
   printf(" Marked: %x, LiveCount: %x\n", mark_size, LiveBytes());
 }
 
 #endif  // DEBUG
 
 } }  // namespace v8::internal