Add tests that failed in CI before

Had to turn an assertion into a condition to make it pass

Author: odersky

compiler/src/dotty/tools/dotc/cc/CaptureOps.scala

@@ -331,8 +331,7 @@ extension (tp: Type)
   def boxed(using Context): Type = tp.dealias match
     case tp @ CapturingType(parent, refs) if !tp.isBoxed && !refs.isAlwaysEmpty =>
       tp.annot match
-        case ann: CaptureAnnotation =>
-          assert(!parent.derivesFrom(defn.Caps_CapSet))
+        case ann: CaptureAnnotation if !parent.derivesFrom(defn.Caps_CapSet) =>
           AnnotatedType(parent, ann.boxedAnnot)
         case ann => tp
     case tp: RealTypeBounds =>

tests/pos-custom-args/captures/cap-paramlist8-desugared.scala

@@ -0,0 +1,28 @@
+  import language.experimental.captureChecking
+  import caps.cap
+
+  trait Ctx[T >: Nothing <: Any]() extends Object
+
+  def test: Unit =
+    {
+      val x: Any^{cap} = ???
+      val y: Any^{cap} = ???
+      object O {
+        val z: Any^{cap} = ???
+      }
+      val baz3:
+        Int -> [C >: caps.CapSet <: caps.CapSet^,
+          D >: caps.CapSet <: caps.CapSet^{C^}, E >: caps.CapSet <:
+          caps.CapSet^{C^, x}] => () -> [F >: caps.CapSet^{x, y} <:
+          caps.CapSet^{C^, E^}] => (x: Int) -> (Ctx[F]) ?-> Int
+        = (i: Int) => [
+        C >: _root_.scala.caps.CapSet <: _root_.scala.caps.CapSet^{cap},
+        D >: _root_.scala.caps.CapSet <: _root_.scala.caps.CapSet^{C^},
+        E >: _root_.scala.caps.CapSet <: _root_.scala.caps.CapSet^{C^, x}] =>
+        () => [
+        F
+            >: _root_.scala.caps.CapSet^{x, y} <:
+            _root_.scala.caps.CapSet^{C^, E^}
+        ] => (x: Int) => (ev: Ctx[F]) ?=> 1
+      ()
+    }