Add type declaration for self_in_

[PalumboN]

@ivojawer started to validate the type declarations.

We need to decide what to do for 'self_in_blah' cases.

[guillep]

Some more details. @ivojawer is working on https://github.com/pharo-project/pharo-vm/issues/598.

Now, when adding validations, we detected that self is considered a local declaration with a type (makes sense) but that is not in the list of locals (makes sense too). In addition, when translating code from structures, a separate variable called self_in_[type] is defined for those methods with the type of the structure.

All those cases should probably be correctly taken into account.

[guillep]

@PalumboN should this be a subissue of #598?

[PalumboN]

Mmmm I think yes, at least to not fail with this kind of declaration.