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 with1;
struct S
{
    int i;
    float f;
}
void main()
{
    S s;
    with(s)
    {
        i = 0;
        f = 3.5;
    }
    assert(s.i == 0);
    assert(s.f == 3.5);
}