It turns out implementing Hash alone is not very useful, as
std::collection::HashMap keys are required to implement both Hash and
Eq.
Co-authored-by: Nikhil Benesch <nikhil.benesch@gmail.com>
I realized a moment too late that I'd missed a type name in
when removing the "SQL" prefix from types in ac555d7e8. As far as I can
tell, this was the only oversight.