Drop assertion in TypeMap

The deleted assertion could fail for code that was
erroneous.

- Enable new hk scheme.

Author: odersky

src/dotty/tools/dotc/config/Config.scala

@@ -10,7 +10,7 @@ object Config {
 
   final val checkCacheMembersNamed = false
 
-  final val newHK = false
+  final val newHK = true
 
   /** When updating a constraint bound, check that the constrained parameter
    *  does not appear at the top-level of either of its bounds.
@@ -80,9 +80,11 @@ object Config {
   final val checkProjections = false
 
   /** If this flag is set it is checked that &/| only apply to types
-   *  that are either both hk types or both * types.
+   *  that are either both hk types or both * types. Should be used
+   *  only for debugging as there a generic class without arguments
+   *  can be produced in an And by Implicits.liftToClasses.
    */
-  final val checkKinds = true
+  final val checkKinds = false
 
   /** The recursion depth for showing a summarized string */
   final val summarizeDepth = 2

src/dotty/tools/dotc/core/Types.scala

@@ -2356,8 +2356,7 @@ object Types {
   object OrType {
     def apply(tp1: Type, tp2: Type)(implicit ctx: Context) = {
       assertUnerased()
-      if (Config.checkKinds)
-        assert((tp1.knownHK - tp2.knownHK).abs <= 1, i"$tp1 | $tp2")
+      if (Config.checkKinds) assert((tp1.knownHK - tp2.knownHK).abs <= 1, i"$tp1 | $tp2")
       unique(new CachedOrType(tp1, tp2))
     }
     def make(tp1: Type, tp2: Type)(implicit ctx: Context): Type =
@@ -3582,7 +3581,6 @@ object Types {
             try this(arg)
             finally variance = saved
           }
-          assert(tp.args.length == tp.typeParams.length, tp)
           derivedAppliedType(tp, this(tp.tycon),
               tp.args.zipWithConserve(tp.typeParams)(mapArg))