The goal of Trac #11371 is to enforce an invariant, by converting calls to substTyUnchecked
to substTy
. Those functions do the same thing, but the second one also checks an invariant.
This check was initially an assertion, but later was downgraded to a warning. Here, I'm restoring the assertion, and converting bad calls into substTyUnchecked
. This way, we can guard against regressions and slowly work towards removing the calls to substTyUnchecked
. I'm also adding a regression test to Trac #13951.