Fix #11464: avoid leaking Range

Using `Range` creates issues of avoid leaking `Range` outside of type
approximation. It's better to eliminate `LazyRef` without resorting to
`Range`.

Author: liufengyun

compiler/src/dotty/tools/dotc/core/TypeOps.scala

@@ -439,7 +439,9 @@ object TypeOps:
           val lo1 = apply(lo)
           if (lo1 ne lo) lo1 else tp
         case tp: LazyRef if isExpandingBounds =>
-          emptyRange
+          if variance == 1 then defn.AnyType
+          else if variance == -1 then defn.NothingType
+          else TypeBounds.empty
         case _ =>
           mapOver(tp)
       }

tests/pos/i11464.scala

@@ -0,0 +1,16 @@
+trait Txn[T <: Txn[T]]
+
+trait Adjunct
+
+trait Type0
+trait Type[A1, Repr[~ <: Txn[~]] <: Expr[~, A1]] extends Type0
+
+object Expr {
+  def test(peer: Type0): Adjunct = {
+    new AdjunctImpl(peer.asInstanceOf[Type[Any, ({ type R[~ <: Txn[~]] <: Expr[~, Any] }) # R]])
+  }
+}
+
+trait Expr[T <: Txn[T], +A]
+
+class AdjunctImpl[A, E[~ <: Txn[~]] <: Expr[~, A]](tpe: Type[A, E]) extends Adjunct