This was accidentally broken in r287024
Sorry about Herald adding me as a reviewer. I need to fix my filters.
Isn't this more compact as:
return MakeCXType(A.getKind() == TemplateArgument::Type ? A.getAsType() : QualType(), TU);
Why not inline the template arguments?
Use auto, the type is obvious.
Turns out we already have another patch that fixes the same problem: D26907