[Ironruby-core] defined?(xxx) behaves differently when called from Silverlight

[Thibaut Barrère]

Hey,

I finally removed all the bits of Silverlight (/Library/Internet
Plug-Ins/Silverlight* , /Library/Receipts/Silverlight*.pkg) and
reinstalled SL2.

It now works as expected. I didn't find some way to understand what
really happened, but the issue is solved anyway.

thanks for your support,

-- Thibaut