Added support for using a temporary to implement emulated ABI return from inline asm, could be easier to use, but I think this will do. It's so extremely target dependent in any case that doing a completely generic approach seems hard.

module bug43;

struct S
{
    ubyte[3] vals;
}

void func(ubyte[3] v)
{
}

void main()
{
    S s;
    func(s.vals);
}