[Mono-dev] not implemented destructor in FontNameConverter

[Andrew Skiba]

As a temporary solution I committed TARGET_JVM so that this destructor
will not be present in our build, but probably it's worth to do same for
Mono, too.

> 
> I wonder, what was the need to throw NotImplementedException 
> in FontNameConverter destructor? What will do GC when 
> destructor fails in such way? The code is in FontConverter.cs:283