Fix --expose-debug-as with number as argument.

src/bootstrapper.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/bootstrapper.h"
 
 #include "src/accessors.h"
 #include "src/code-stubs.h"
 #include "src/extensions/externalize-string-extension.h"
 #include "src/extensions/free-buffer-extension.h"
@@ skipping 2186 matching lines @@
     // debugger but without tanking the whole context.
     Debug* debug = isolate->debug();
     if (!debug->Load()) return true;
     Handle<Context> debug_context = debug->debug_context();
     // Set the security token for the debugger context to the same as
     // the shell native context to allow calling between these (otherwise
     // exposing debug global object doesn't make much sense).
     debug_context->set_security_token(native_context->security_token());
     Handle<String> debug_string =
         factory->InternalizeUtf8String(FLAG_expose_debug_as);
+    uint32_t index;
+    if (debug_string->AsArrayIndex(&index)) return true;
     Handle<Object> global_proxy(debug_context->global_proxy(), isolate);
     JSObject::AddProperty(global, debug_string, global_proxy, DONT_ENUM);
   }
   return true;
 }
 
 
 static uint32_t Hash(RegisteredExtension* extension) {
   return v8::internal::ComputePointerHash(extension);
 }
@@ skipping 474 matching lines @@
   return from + sizeof(NestingCounterType);
 }
 
 
 // Called when the top-level V8 mutex is destroyed.
 void Bootstrapper::FreeThreadResources() {
   DCHECK(!IsActive());
 }
 
 } }  // namespace v8::internal