Context

Following !2335 (closed), this MR migrates the parse_instr function to produce the new IR.

As a consequence, this MR removes the original IR and the temporary translation introduced by !2335 (closed).

To simplify the review process, the patch is intentionally minimal in the sense that it only:

modifies the output type of parse_instr to produce instruction of the new IR (parameterized by a continuation) ;
enforces the invariant that the stack type contains always at least one element.

Further refactorings of the elaboration will be needed to improve its readability.

Checklist

~~[ ] Document the interface of any function added or modified (see the coding guidelines)~~
~~[ ] Provide automatic testing (see the testing guide).~~
~~[ ] Add item in the Development Version section of CHANGES.md (only for new features and bug fixes).~~

Edited Jan 28, 2021 by Yann Regis-Gianas