Reduce to four errors

Author: liufengyun

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

@@ -523,6 +523,7 @@ class SpaceEngine(implicit ctx: Context) extends SpaceLogic {
           val mt = pt.instantiate(tvars).asInstanceOf[MethodType]
           // println("mt.paramInfos(0) = " + mt.paramInfos(0))
           scrutineeTp <:< mt.paramInfos(0)
+          mt.paramInfos(0) <:< scrutineeTp
           isFullyDefined(mt, ForceDegree.flipBottom)
           // println("mt = " + mt)
           mt