Merge pull request #6099 from dotty-staging/fix-#6083

Fix #6083: Dealias before kind checking

Author: smarter

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

@@ -211,7 +211,10 @@ class TypeApplications(val self: Type) extends AnyVal {
 
   /** Is self type of kind "*"? */
   def hasSimpleKind(implicit ctx: Context): Boolean =
-    typeParams.isEmpty && !self.hasAnyKind
+    typeParams.isEmpty && !self.hasAnyKind || {
+      val alias = self.dealias
+      (alias ne self) && alias.hasSimpleKind
+    }
 
   /** If self type is higher-kinded, its result type, otherwise NoType.
    *  Note: The hkResult of an any-kinded type is again AnyKind.

tests/pos/i6083.scala

@@ -0,0 +1,3 @@
+type K[T <: AnyKind] = T
+val a: K[Int] = 1
+val b: K[List][Int] = Nil