Fix warnings on Win64.

src/compiler.cc

 // Copyright 2009 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 159 matching lines @@
   bool is_json = (validate == Compiler::VALIDATE_JSON);
   if (is_eval || is_json) {
     script->set_compilation_type(
         is_json ? Smi::FromInt(Script::COMPILATION_TYPE_JSON) :
                                Smi::FromInt(Script::COMPILATION_TYPE_EVAL));
     // For eval scripts add information on the function from which eval was
     // called.
     if (is_eval) {
       JavaScriptFrameIterator it;
       script->set_eval_from_function(it.frame()->function());
-      int offset = it.frame()->pc() - it.frame()->code()->instruction_start();
+      int offset = static_cast<int>(
+          it.frame()->pc() - it.frame()->code()->instruction_start());
       script->set_eval_from_instructions_offset(Smi::FromInt(offset));
     }
   }
 
   // Notify debugger
   Debugger::OnBeforeCompile(script);
 #endif
 
   // Only allow non-global compiles for eval.
   ASSERT(is_eval || is_global);
@@ skipping 917 matching lines @@
 
 void CodeGenSelector::VisitThisFunction(ThisFunction* expr) {
   BAILOUT("ThisFunction");
 }
 
 #undef BAILOUT
 #undef CHECK_BAILOUT
 
 
 } }  // namespace v8::internal