TODO

* Improve generated code readability, check current github PR

* Better recognition of out parameters

* Recognize primitive implementation of sum types in function inputs

* Specialize extension functions to use the extension functor argument
  when possible.

* Liveness analysis: make sure that the GC don't collect values that live
on the C side

* Expose record setter

Done:

* Variable-length output array:
  Extract correctly the tuple index, array from the function definition

* Structure_type handling:
  The (s_type, p_next) vulkan idiom should be mapped to
  `Stype(p_next) and made optional in smart record constructor when there is
  only one possible `Stype. The possible values need to be extracted from the vulkan
  spec.

* Path field array index:
  Output Array lenght are sometimes defined in term of input.fields_path

* Be more cautious when identifying out parameters

* Remove useless prefix in name
  e.g. p_, s_, pp_

* Formatter for record types

* Handle shared size between array input

* Handle constant-size arrays

* Constructor for union type