Refactor inlining of function calls

https://github.com/HaxeFoundation/haxe/blob/84f74018ca4b61f0aa0be4085ad64369d02ca474/src/optimization/inline.ml#L553-L563

> I agree with the sentiment that we don't have to map the argument expressions, but I'm not sure if this is the correct way to go about it.

> Something we could try is to run the mapping earlier, i.e. before inline_params. I don't know if we're missing some cases where we want to map that way though (maybe some abstract this situation).
>
> Something else we could try eventually is to lose the entire map_expr_type part and instead handle this manually during our initial map in type_inline. That would have the added benefit of being faster because map_expr_type is quite heavy.

https://github.com/HaxeFoundation/haxe/pull/8658#issuecomment-522609446