chore: Remove unnecessary Darwin/Glibc includes and clean up some numerics usage

[hassila]

No description provided.

[codecov]

Codecov Report

Merging #33 (93516d3) into main (742b566) will increase coverage by 0.07%.
The diff coverage is 100.00%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #33      +/-   ##
==========================================
+ Coverage   82.64%   82.71%   +0.07%     
==========================================
  Files          18       18              
  Lines        2114     2123       +9     
==========================================
+ Hits         1747     1756       +9     
  Misses        367      367              

Impacted Files	Coverage Δ
...ort/MallocStats/MallocStatsProducer+jemalloc.swift	73.10% <ø> (ø)
Sources/BenchmarkSupport/BenchmarkRunner.swift	81.27% <100.00%> (+0.13%)	⬆️
Sources/Statistics/Statistics.swift	88.67% <100.00%> (+0.26%)	⬆️

Impacted Files	Coverage Δ
...ort/MallocStats/MallocStatsProducer+jemalloc.swift	73.10% <ø> (ø)
Sources/BenchmarkSupport/BenchmarkRunner.swift	81.27% <100.00%> (+0.13%)	⬆️
Sources/Statistics/Statistics.swift	88.67% <100.00%> (+0.26%)	⬆️

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