Try to fix Win64 build

src/debug.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 1859 matching lines @@
 
       // Find the function and patch return address.
       for (JavaScriptFrameIterator it(isolate_); !it.done(); it.Advance()) {
         JavaScriptFrame* frame = it.frame();
         // If the current frame is for this function in its
         // non-optimized form rewrite the return address to continue
         // in the newly compiled full code with debug break slots.
         if (frame->function()->IsJSFunction() &&
             frame->function() == *function &&
             frame->LookupCode()->kind() == Code::FUNCTION) {
-          int delta = frame->pc() - current_code->instruction_start();
+          intptr_t delta = frame->pc() - current_code->instruction_start();
           int debug_break_slot_count = 0;
           int mask = RelocInfo::ModeMask(RelocInfo::DEBUG_BREAK_SLOT);
           for (RelocIterator it(*new_code, mask); !it.done(); it.next()) {
             // Check if the pc in the new code with debug break
             // slots is before this slot.
             RelocInfo* info = it.rinfo();
             int debug_break_slot_bytes =
                 debug_break_slot_count * Assembler::kDebugBreakSlotLength;
-            int new_delta =
+            intptr_t new_delta =
                 info->pc() -
                 new_code->instruction_start() -
                 debug_break_slot_bytes;
             if (new_delta > delta) {
               break;
             }
 
             // Passed a debug break slot in the full code with debug
             // break slots.
             debug_break_slot_count++;
@@ skipping 1487 matching lines @@
     {
       Locker locker;
       Isolate::Current()->debugger()->CallMessageDispatchHandler();
     }
   }
 }
 
 #endif  // ENABLE_DEBUGGER_SUPPORT
 
 } }  // namespace v8::internal