Detect cyclic includes between generic modules

[HertzDevil]

The compiler reports an error when a module cyclically includes itself, but this doesn't work when any generic module is part of the cycle, so this breaks with a stack overflow:

module Foo(T)
  include self
end

This PR extends the checks to compare generic module instances by their underlying generic modules so that these cases are detected. The generic type arguments don't matter, as ultimately every instantiation of the same module will lead to a recursive include cycle:

module Foo(T)
  include Foo(Int32) # Foo(Int32) includes Foo(Int32)
end

Referencing self inside generic type arguments is still allowed, e.g. Comparable(self), because generic type arguments cannot be used as an included type:

module Comparable(T)
  include T # Error: T is not a module, it's a T
end

class String
  include Comparable(self) # okay
end

[beta-ziliani]

Thanks!