Fix #9206: Add missing type symbol in Scala2 constructors

Author: nicolasstucki

compiler/src/dotty/tools/dotc/core/unpickleScala2/Scala2Unpickler.scala

@@ -57,7 +57,10 @@ object Scala2Unpickler {
 
   def addConstructorTypeParams(denot: SymDenotation)(implicit ctx: Context): Unit = {
     assert(denot.isConstructor)
-    denot.info = PolyType.fromParams(denot.owner.typeParams, denot.info)
+    val typeParams = denot.owner.typeParams
+    denot.info = PolyType.fromParams(typeParams, denot.info)
+    if typeParams.nonEmpty then
+      denot.rawParamss = typeParams :: denot.rawParamss
   }
 
   /** Convert array parameters denoting a repeated parameter of a Java method

tests/run-macros/i9206/Macros_1.scala

@@ -0,0 +1,11 @@
+
+import scala.quoted.{Expr, QuoteContext}
+
+object Inspect {
+  inline def inspect[T <: AnyKind]: String = ${ inspectTpe[T] }
+
+  def inspectTpe[T <: AnyKind](using tpe: quoted.Type[T], qctx0: QuoteContext): Expr[String] = {
+    val tree = summon[quoted.Type[T]].unseal.tpe.typeSymbol.tree
+    Expr(tree.show)
+  }
+}

tests/run-macros/i9206/Test_2.scala

@@ -0,0 +1,10 @@
+import Inspect._
+
+object Test extends App {
+  inspect[scala.collection.immutable.List[Int]]
+  inspect[java.lang.String]
+  inspect[String]
+  inspect[List[Unit]]
+  inspect[Some[Unit]]
+  inspect[Tuple1[Unit]]
+}