Update codegen to (hopefully) work correctly with newer LLVM trunk, where there's no longer a Fast flag. (It has been replaced by an optimization level) Untested because I haven't compiled that recent an LLVM yet :).

#ifndef LDC_IR_IRDTYPE_H
#define LDC_IR_IRDTYPE_H

#include <set>

namespace llvm {
    class PATypeHolder;
}

struct IrDType
{
    IrDType();
    llvm::PATypeHolder* type;
};

#endif