Fix bug relating to type conversion in function calls

[MarkMcCaskey]

resolves #1596

I attempted to use constant expressions so we didn't have to duplicate the macro, but std::mem::transmute is a compile error if you attempt to transmute from A to B where size_of(A) != size_of(B), even if it's in a branch like if false

edit: this pr no longer uses any unsafe code, perhaps we should review making those functions const now

Review

• Add a short description of the the change to the CHANGELOG.md file

[codecov-commenter]

Codecov Report

Merging #1602 into master will decrease coverage by 0.00%.
The diff coverage is 50.00%.

@@            Coverage Diff             @@
##           master    #1602      +/-   ##
==========================================
- Coverage   31.77%   31.76%   -0.01%     
==========================================
  Files         185      185              
  Lines       27015    27017       +2     
==========================================
- Hits         8583     8582       -1     
- Misses      18432    18435       +3     

Impacted Files	Coverage Δ
lib/api/src/externals/function.rs	35.92% <50.00%> (-0.36%)	⬇️
lib/compiler-cranelift/src/config.rs	60.00% <0.00%> (-2.50%)	⬇️
lib/api/src/native.rs	51.51% <0.00%> (+3.03%)	⬆️

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[MarkMcCaskey]

bors try

[bors]

try

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[MarkMcCaskey]

bors r+

[bors]

Build succeeded:

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