Increment mismatched type. Fixes #722

[kamphaus]

Fixes #722

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This change is 

[codecov]

Codecov Report

Merging #723 into master will decrease coverage by 0.02%.
The diff coverage is 65.21%.

@@            Coverage Diff             @@
##           master     #723      +/-   ##
==========================================
- Coverage   81.71%   81.68%   -0.03%     
==========================================
  Files         165      165              
  Lines        9199     9218      +19     
==========================================
+ Hits         7517     7530      +13     
- Misses       1271     1274       +3     
- Partials      411      414       +3

Impacted Files	Coverage Δ
transpiler/operators.go	78.48% <100%> (+0.03%)	⬆️
transpiler/unary.go	70.89% <61.9%> (-0.56%)	⬇️
transpiler/call.go	70% <0%> (+0.79%)	⬆️

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[elliotchance]

Reviewed 3 of 3 files at r1.
Review status: all files reviewed at latest revision, all discussions resolved.

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