If we are doing a rename from a C#/VB symbol, and an F# project depends
on that project, we might end up walking into non-C#/VB projects and
we will crash. This prevents the crash.

There were two ways I could fix this bug: one would be to update
GetDocumentsAffectedByRename to exclude them up front. The other option
is to deal with those at the call sites when we fail to find a service.
I'm electing to do the later as that allows light-up by the appropriate
language services if they wanted to do that down the road.