What I certainly don't want to do is to have to cross-reference IDs
with arrays, nor start to stack endless if/else that are even more
painful to deal with, or have to renumber everything by hand once in
a while.
But again, I'm open to better proposals. I reached the limits of my
imagination there, but I do value the ability to "yyp" one line, change
two arguments and gain one extra test for a different combination, and
I really do not want to lose that simplicity. Note that for more complex
tests, it's trivial to add a dedicated function and that's what was done
for getdents64() which also serves as an example.