GLResource.cs has unnecessary `GC.KeepAlive(this)` call.

[john-h-k]

this cannot be disposed during execution of one of its methods. Dispose is an instance member. Call is unnecessary and will just slightly hurt perf

[JcBernack]

These articles say something different:

• https://devblogs.microsoft.com/oldnewthing/20100813-00/?p=13153
• https://blogs.msdn.microsoft.com/oldnewthing/20100810-00/?p=13193/

An object can become eligible for collection during execution of a method on that very object.

[john-h-k]

Yes, it is useful in a finalizer. But this is in Dispose, where it is useless

[john-h-k]

Put it in the actual finalizer, not the top level Dispose method