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

R=jkummerow@chromium.org
BUG=405491
LOG=N

Review URL: https://codereview.chromium.org/468803004

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@23228 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/bootstrapper.cc

@@ -2204,6 +2204,8 @@ bool Genesis::InstallSpecialObjects(Handle<Context> native_context) {
     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);
   }

test/mjsunit/regress/regress-crbug-405491.js

+// 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.
+
+// Flags: --expose-debug-as 1