Add tests for augmenting assigns recursively

[JSAbrahams]

Summary

Add tests for augmenting assigns recursively

Added Tests

Happy

• Assign in if
• Assign in nested if
• Assign in match
• Assign in handle
• For both adding assign and return, test that last statement in block augmented

[codecov[bot]]

Codecov Report

Merging #376 (5aea625) into v-3-3-4 (9982cc3) will decrease coverage by 0.02%. The diff coverage is n/a.

@@             Coverage Diff             @@
##           v-3-3-4     #376      +/-   ##
===========================================
- Coverage    87.00%   86.97%   -0.03%     
===========================================
  Files          109      109              
  Lines        11950    11950              
===========================================
- Hits         10397    10394       -3     
- Misses        1553     1556       +3     

Impacted Files	Coverage Δ
src/check/context/clss/mod.rs	86.52% <0.00%> (-2.13%)	:arrow_down: