Typeclass on eqtype is not resolved when at the end of a type in lax mode (hence dependency loading)

[TWal]

See this minimal repro:

class machin (a:eqtype) = {
  chose: unit;
}

noeq type truc (a:eqtype) {|machin a|} = {
  muche: unit;
}

instance bidule: machin nat = { chose = () }

val toto: truc nat
let toto = {
  muche = ();
}

If we replace eqtype by Type0 then the bug don't appear.
A workaround is to do val toto: truc nat #_

[mtzguido]

Thanks Théophile! I had noticed some similar weirdness but didn't have a small repro for it.