Compiler upgrade checks don't allow alpha equivalence between datatypes

[dylant-da]

[daravep]

Likely revealing my ignorance, but what do you mean here? Our assumption in upgrading is that data types can't be renamed. So do you want to support renaming?

[dylant-da]

This is about alpha equivalence of variable names - e.g.

data X a = X { field1: a }

should be equivalent to

data X b = X { field1 : b }

And furthermore the following should be an upgrade:

data X b = X { field1: b, field2: Optional b }

[dylant-da]

Fixed by https://github.com/digital-asset/daml/pull/20016 and https://github.com/digital-asset/daml/pull/20024 on 2.x, https://github.com/digital-asset/daml/pull/20025 on 3.x