MatchType not normalised for mirror synthesis when aliased

[EugeneFlesselle]

Minimized code

inline def check1[Tps <: NonEmptyTuple]: Unit =
  summonInline[Mirror.Of[Tuple.Head[Tps]]]

inline def check2[Tps <: NonEmptyTuple]: Unit =
  type FromType = Tuple.Head[Tps]
  summonInline[Mirror.Of[FromType]]

@main def Test: Unit =
  check1[Option[Int] *: EmptyTuple] // Ok
  check2[Option[Int] *: EmptyTuple] // Error: FromType is widened to Any in Syntheziser

Output

13 |  check2[Option[Int] *: EmptyTuple] // Error: FromType is widened to Any in Syntheziser
   |  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |No given instance of type scala.deriving.Mirror.Of[FromType] was found. Failed to synthesize an instance of type scala.deriving.Mirror.Of[FromType]:
   |    * class Any is not a generic product because it is not a case class
   |    * class Any is not a generic sum because it is not a sealed class
   |--------------------------------------------------------------------------------------------------------------------

Expectation

FromType alias should make no difference.