core: (rewriting) Fix recursive type conversion in block arguments for nested regions

[webmiche]

closes #2857

Solves the issue mentioned there and adds the reported testcase as a regression test.

Before, this was actually quite broken as not applying the recursive rewrite, but the normal rewrite, to the region would actually mean that the produced func_op did not even verify (the function_type attribute got rewritten properly, whereas the entry_block args would still have the old type).

The reason why the old type was being printed is that the print_func_op_like-utility function defaults to printing the entry_block arguments in some cases.

[webmiche]

@francescodaghero feel free to also comment/leave a review :)

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 89.86%. Comparing base (f7f1471) to head (c16e08b).
Report is 5 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2871      +/-   ##
==========================================
- Coverage   89.87%   89.86%   -0.01%     
==========================================
  Files         396      397       +1     
  Lines       49827    49966     +139     
  Branches     7683     7713      +30     
==========================================
+ Hits        44780    44903     +123     
- Misses       3837     3846       +9     
- Partials     1210     1217       +7     

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[webmiche]

@superlopuh do you think we can merge this without @PapyChacal s approval? It seems like fairly obvious fix to me, but I am not very deep in the intricacies of the TypeConversion stuff.

[superlopuh]

Hmm, reading the source code more, it seems that _convert_type_rec is really the thing to call everywhere, and I'm not sure why it wasn't in the first place. There's a check for self.recursive in the private method, so it should do the right thing without checking for it twice. I would probably change it to that and then merge, I'm not sure when Emilien is back from holidays but we can fix it then if anything breaks that we're not aware of.

[webmiche]

Hmm, yeah fair enough. I am honestly not sure what we want this API to look like exactly, but your change sounds reasonable.

[webmiche]

I will wait for the CI to pass and then merge.