fix: Exporting converging control flow edges

[zrho]

Fixes #1889.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 86.56%. Comparing base (f7eab22) to head (db02256).
Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1890      +/-   ##
==========================================
+ Coverage   86.55%   86.56%   +0.01%     
==========================================
  Files         195      195              
  Lines       35693    35724      +31     
  Branches    32506    32537      +31     
==========================================
+ Hits        30895    30926      +31     
  Misses       3011     3011              
  Partials     1787     1787              

Flag	Coverage Δ
python	92.34% <ø> (ø)
rust	86.00% <100.00%> (+0.01%)	⬆️

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[ss2165]

Please add a test that fails without this fix.

Constructing the links struct looks like it adds a non-trivial amount of pre-computation. Do you have a measure of performance impact?

[ss2165]

does this change make sense?

[zrho]

Yes. This is a test that should have failed but I overlooked it earlier. It's correct now. So this is the test you asked for.

I measured the performance impact and it was very small.