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.

class A {
    int i;
    int l;
    this(bool b,bool b2=false) {
        if (b) this = new B;
        i = 4;
        if (b2) this = new C;
        l = 64;
    }
}
class B : A{
    this() {
        super(false);
    }
}
class C : A{
    this() {
        super(false);
    }
}
void main() {
}