Drop HigherKinded flag

Author: odersky

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

@@ -222,8 +222,8 @@ object Flags {
   /** Labeled with `final` modifier */
   val (Final @ _, _, _) = newFlags(6, "final")
 
-  /** A method symbol */
-  val (_, Method @ _, HigherKinded @ _) = newFlags(7, "<method>", "<higher kinded>") // TODO drop HigherKinded
+  /** A method symbol / a super trait */
+  val (_, Method @ _, SuperTrait @ _) = newFlags(7, "<method>", "super")
 
   /** A (term or type) parameter to a class or method */
   val (Param @ _, TermParam @ _, TypeParam @ _) = newFlags(8, "<param>")
@@ -439,7 +439,7 @@ object Flags {
    */
   val FromStartFlags: FlagSet = commonFlags(
     Module, Package, Deferred, Method, Case, Enum,
-    HigherKinded, Param, ParamAccessor,
+    SuperTrait, Param, ParamAccessor,
     Scala2SpecialFlags, MutableOrOpen, Opaque, Touched, JavaStatic,
     OuterOrCovariant, LabelOrContravariant, CaseAccessor,
     Extension, NonMember, Implicit, Given, Permanent, Synthetic,

compiler/src/dotty/tools/dotc/semanticdb/ExtractSemanticDB.scala

@@ -100,7 +100,7 @@ class ExtractSemanticDB extends Phase:
 
     private def excludeChildren(sym: Symbol)(using Context): Boolean =
       !sym.exists
-      || sym.isAllOf(HigherKinded | Param)
+      || sym.is(Param) && sym.info.bounds.hi.isInstanceOf[Types.HKTypeLambda]
 
     /** Uses of this symbol where the reference has given span should be excluded from semanticdb */
     private def excludeUse(qualifier: Option[Symbol], sym: Symbol)(using Context): Boolean =

compiler/src/dotty/tools/dotc/typer/Namer.scala

@@ -404,7 +404,6 @@ class Namer { typer: Typer =>
               case _: TypeBoundsTree | _: MatchTypeTree =>
                 flags |= Deferred // Typedefs with Match rhs classify as abstract
               case LambdaTypeTree(_, body) =>
-                flags |= HigherKinded
                 analyzeRHS(body)
               case _ =>
                 if rhs.isEmpty || flags.is(Opaque) then flags |= Deferred