Proc type won't match despite identical signatures

[Stefan_Salewski]

<https://nim-lang.org/docs/manual.html#procedures-closures>
    
    
    nimcall
        is the default convention used for a Nim proc. It is the same as 
fastcall, but only for C compilers that support fastcall.
    closure
        is the default calling convention for a procedural type that lacks any 
pragma annotations.
    
    
    Run