Fix newtype eta-reduction
The eta-reduction we do for newype axioms was generating an inhomogeneous axiom: see #19739 (closed).
This patch fixes it in a simple way; see GHC.Tc.TyCl.Build
Note [Newtype eta and homogeneous axioms]
The eta-reduction we do for newype axioms was generating an inhomogeneous axiom: see #19739 (closed).
This patch fixes it in a simple way; see GHC.Tc.TyCl.Build
Note [Newtype eta and homogeneous axioms]