Fix #11648.

We now check that a CUSK is really a CUSK and issue an error if
it isn't. This also involves more solving and zonking in
kcHsTyVarBndrs, which was the outright bug reported in #11648.

Test cases: polykinds/T11648{,b}

This updates the haddock submodule.

[skip ci]

1 files changed, 0 insertions, 0 deletions

diff --git a/utils/haddock b/utils/haddock
-Subproject ab954263a793d8ced734459d6194a5d89214b66
+Subproject bb994de1ab0c76d1aaf1e39c54158db2526d31f