No need to handle recursive calls separately in the reverse mode

[PetroZarytskyi]

Currently, we declare pullbacks before generating the body. This means that when f is differentiated, f_pullback has already been declared. Therefore, HandleNestedDiffRequest is capable of finding it.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 94.55%. Comparing base (48b76c4) to head (bca7dee).
Report is 1 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1160      +/-   ##
==========================================
- Coverage   94.56%   94.55%   -0.01%     
==========================================
  Files          51       51              
  Lines        8944     8933      -11     
==========================================
- Hits         8458     8447      -11     
  Misses        486      486              

Files with missing lines	Coverage Δ
lib/Differentiator/ReverseModeVisitor.cpp	95.58% <100.00%> (-0.02%)	⬇️

Files with missing lines	Coverage Δ
lib/Differentiator/ReverseModeVisitor.cpp	95.58% <100.00%> (-0.02%)	⬇️

[PetroZarytskyi]

The diff looks like the code was rewritten, although, it just removed the block after if (FD == m_DiffReq.Function &&... and left the else-block as it was. The diff is confusing because of the indentation.

[vgvassilev]

LGTM!

[vgvassilev]

clang-tidy seem to be broken again...