Fix CI

Author: liufengyun

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

@@ -374,7 +374,7 @@ class SpaceEngine(implicit ctx: Context) extends SpaceLogic {
           // cannot use WildcardType for Array[_], due to that
           //   Array[WildcardType] <: Array[Array[WildcardType]]
           // see tests/patmat/t2425.scala
-          TypeErasure.erasure(tp)
+          tp
         case tref: TypeRef if isPatternTypeSymbol(tref.typeSymbol) =>
           WildcardType(tref.underlying.bounds)
         case _ => mapOver(tp)

tests/patmat/i6197b.scala

@@ -0,0 +1,4 @@
+def foo(x: Option[Array[String]]) = x match {
+  case Some(x) =>
+  case None    =>
+}

tests/patmat/i6197c.check

@@ -0,0 +1 @@
+3: Match case Unreachable

tests/patmat/i6197c.scala

@@ -0,0 +1,5 @@
+def foo(x: Option[Any]) = x match {
+  case _: Some[Some[_]] =>
+  case _: Some[_] =>         // unreachable
+  case None    =>
+}