Fix issue 23158

The fix is made based on us doing stripNamedTuple in other parts close
by. Seems like made should in a single place, but I lack the bigger
understanding to figure our where that would be.

Author: eejbyfeldt

compiler/src/dotty/tools/dotc/transform/patmat/Space.scala

@@ -581,7 +581,7 @@ object SpaceEngine {
     var resTp0 = mt.resultType
     if mt.isResultDependent then
       resTp0 = ctx.typeAssigner.safeSubstParam(resTp0, mt.paramRefs.head, scrutineeTp)
-    val resTp = wildApprox(resTp0.finalResultType)
+    val resTp = wildApprox(resTp0.finalResultType).stripNamedTuple
 
     val sig =
       if (resTp.isRef(defn.BooleanClass))

tests/pos/i23158.scala

@@ -0,0 +1,11 @@
+//> using options -Werror
+
+object Unpack {
+  final case class Pair(a: Int, b: Int)
+  def unapply(e: Pair): NamedTuple.NamedTuple[("a", "b"), (Int, Int)] = ???
+
+  val x: Pair = ???
+  x match {
+    case Unpack(_, _) => ???
+  }
+}