Remove an old workaround that was kept around for ABI-compatibility on x86-64 between different LLVM versions. This means LLVM r67588 is required if you want to compile for x86-64, otherwise the backend will assert when you try to return e.g. struct { int i; char c; } from a function. (In particular, this is no longer compatible with LLVM 2.5) It also means that any code returning small structs on x86-64 will probably need to be recompiled in order to be linkable to code compiled with this change.

module switch3;
extern(C) int printf(char*, ...);

void main()
{
    char[] str = "hello";
    int i;
    switch(str)
    {
    case "world":
        i = 1;
        assert(0);
    case "hello":
        i = 2;
        break;
    case "a","b","c":
        i = 3;
        assert(0);
    default:
        i = 4;
        assert(0);
    }
    assert(i == 2);
    printf("SUCCESS\n");
}