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 vararg2;

void func(...)
{
    assert(_arguments.length == 2);
    assert(_arguments[0] is typeid(int));
    int a = *cast(int*)_argptr;
    _argptr += size_t.sizeof;
    assert(_arguments[1] is typeid(int));
    a += *cast(int*)_argptr;
    _argptr += int.sizeof;
    assert(a == 3);
}

void main()
{
    func(1,2);
}