SI-8023 Address review comments around typedHigherKindedType

  - Make `WildCardType` kind polymorphic
  - Factory methods for expected kinds. They are still just
    `Type`-s, though.
  - Check if the type parameter is initialized, rather than
    its owner.
  - Take advantage of these to cleanup `typedAppliedTypeTree`

TODO: is this comment totally accurate? If so, should we
refactor `Kind.FromParams(tparams)` to `Kind.Arity(tparams.length)`?

     // @M: kind-arity checking is done here and in adapt,
     //     full kind-checking is in checkKindBounds (in Infer)

1 files changed, 2 insertions, 0 deletions

diff --git a/src/reflect/scala/reflect/internal/Kinds.scala b/src/reflect/scala/reflect/internal/Kinds.scala
index d48a6c6322..8ae201f045 100644
--- a/src/reflect/scala/reflect/internal/Kinds.scala
+++ b/src/reflect/scala/reflect/internal/Kinds.scala
@@ -326,6 +326,8 @@ trait Kinds {
     private[internal] object StringState {
       def empty: StringState = StringState(Seq())
     }
+    def FromParams(tparams: List[Symbol]): Type = GenPolyType(tparams, AnyTpe)
+    def Wildcard: Type                          = WildcardType
   }
   class ProperTypeKind(val bounds: TypeBounds) extends Kind {
     import Kind.StringState