This reverts commit 9ae1598

Note that the changes in Typer:
```
val unsimplifiedType = result.tpe
simplify(result, pt, locked)
result.tpe.stripTypeVar match
  case e: ErrorType if !unsimplifiedType.isErroneous =>
    errorTree(xtree, e.msg, xtree.srcPos)
  case _ => result
```
cannot be reverted yet since the MatchReducer now also reduces to an `ErrorType` for MatchTypeLegacyPatterns, introduced after 9ae1598.

i18488.scala was only passing because of the bug in the MatchReducer,
as we can see in the subtyping trace:
```
==> isSubType TableQuery[BaseCrudRepository.this.EntityTable] <:< Query[BaseCrudRepository.this.EntityTable, E[Option]]?
  ==> isSubType Query[BaseCrudRepository.this.EntityTable, Extract[BaseCrudRepository.this.EntityTable]] <:<
                Query[BaseCrudRepository.this.EntityTable, E[Option]] (left is approximated)?
    ==> isSubType E[Option] <:< Extract[BaseCrudRepository.this.EntityTable]?
      ==> isSubType [T[_$1]] =>> Any <:< Extract?
        ==> isSubType Any <:< Extract[T]?
          ==> isSubType Any <:< T match { case AbstractTable[t] => t } <: t (right is approximated)?
            ==> isSubType Any <:< <error Match type reduction failed since selector T
                                   matches none of the cases
                                   case AbstractTable[t] => t> (right is approximated)?
            <== isSubType Any <:< <error Match type reduction failed since selector T
                                   matches none of the cases
                                   case AbstractTable[t] => t> (right is approximated) = true
          <== isSubType Any <:< T match { case AbstractTable[t] => t } <: t (right is approximated) = true
        <== isSubType Any <:< Extract[T] = true
      <== isSubType [T[_$1]] =>> Any <:< Extract = true
      ...
    <== isSubType Extract[BaseCrudRepository.this.EntityTable] <:< E[Option] = true
  <== isSubType Query[BaseCrudRepository.this.EntityTable, Extract[BaseCrudRepository.this.EntityTable]] <:<
                Query[BaseCrudRepository.this.EntityTable, E[Option]] (left is approximated) = true
<== isSubType TableQuery[BaseCrudRepository.this.EntityTable] <:< Query[BaseCrudRepository.this.EntityTable, E[Option]] = true
```