Fix of t1236: higher-kinded

(and also of t0625, which reappeared).

Several fixes were made. In summary:

1. Naming and representation of KigherKinded traits changed. It's now $HigherKinded$NIP where
the letters after the second $ indicate variance (N)egative, (I)nvariant, (P)ositive. The HKtraits
themselves are always non-variant in their parameters.

2. When deriving refined types over higher-kinded types, the variance of a type alias
is the variance of the new type constructor.

3. isSubTypeHK was changed, as was the position from where it is called.

4. appliedTo also works for PolyTypes.

1 files changed, 2 insertions, 0 deletions

diff --git a/src/dotty/tools/dotc/typer/Namer.scala b/src/dotty/tools/dotc/typer/Namer.scala
index 7885e85ac..361de802c 100644
--- a/src/dotty/tools/dotc/typer/Namer.scala
+++ b/src/dotty/tools/dotc/typer/Namer.scala
@@ -549,6 +549,8 @@ class Namer { typer: Typer =>
                   else NoType
               }
               val iResType = iInstInfo.finalResultType.asSeenFrom(site, cls)
+              if (iResType.exists)
+                typr.println(s"using inherited type; raw: $iRawInfo, inst: $iInstInfo, inherited: $iResType")
               tp & iResType
             }
           }