GHC.Prim.~# shows up unexpectedly in a pattern synonym type

When I load

data T a where
  MkT :: Bool -> T Bool

pattern P x <- MkT x

into GHCi and ask :info P, I get

pattern P :: () => t GHC.Prim.~# Bool => Bool -> T t

That should say t ~ Bool without -fprint-equality-relations.

Trac metadata

Trac field	Value
Version	8.0.1
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
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