Macro builtins 

macro_rules! builtins {
    () => { ... };
    ($(#[$attr:meta])* pub unsafe extern "C" fn $name:ident($ecx:ident : &mut EvmContext<'_> $(, $rest_i:ident : $rest_t:ty)* $(,)?) -> BuiltinResult $block:block $($more:tt)*) => { ... };
    ($item:item $($rest:tt)*) => { ... };
}