Re: Enable the MACRO _DEBUG_CHECK_NULL_

[bu qi cheng]

Currently, there are two kind modifier for TauCheckNull: Exception and
DefArg.

Inst* InstFactory::makeTauCheckNull(Opnd* dst, Opnd* base) {
    assert(dst->getType()->tag == Type::Tau);
    return makeInst(Op_TauCheckNull, *
Modifier(Exception_Sometimes)|Modifier(DefArgNoModifier),*
                    Type::Tau, dst, base);
}
Maybe, it's not suitable to use Modifer "DefArg" (NonNullThisArg) for
chknull instruction (Although it's right curerntly).
I think SrcNonNullModifier is more suitable to be used to solve the problem.


Any commnets?

Thanks!

Buqi