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 switch2;
extern(C) int printf(char*, ...);

void main()
{
    int i = 2;
    switch(i)
    {
    case 0: assert(0);
    case 1,2: printf("hello world\n"); break;
    default: assert(0);
    }
}