Add regression test for #23952 (#26546)

Closes #23952

The issue was fixed by #26063. Adds a regression test.

## Have you relied on LLM-based tools in this contribution?

No

## How was the solution tested?

New automated tests (including the issue's reproducer, if applicable)

Author: warcholjakub

tests/pos/i23952.scala

@@ -0,0 +1,25 @@
+trait Typeclass[I]
+
+sealed trait Enumm:
+  type Insider
+
+object Enumm:
+  case object Enumm1 extends Enumm:
+    case class Insider()
+
+    object Insider:
+      given t: Typeclass[Insider] = new Typeclass[Insider] {}
+
+class Foo
+implicit val f: Foo = new Foo
+
+def pathDependentTypeDefaultParam(tpe: Enumm)(i: tpe.Insider, p: Int = 0)(using t: Typeclass[tpe.Insider]): Int = p
+def defaultParamNotPDT(tpe: Enumm)(i: tpe.Insider, p: Int = 0)(using t: Foo): Int = p
+def pathDependentTypeDefaultParamOwnList(tpe: Enumm)(i: tpe.Insider)(p: Int = 0)(using t: Typeclass[tpe.Insider]): Int = p
+
+def main =
+  pathDependentTypeDefaultParam(Enumm.Enumm1)(Enumm.Enumm1.Insider())
+  pathDependentTypeDefaultParam(Enumm.Enumm1)(Enumm.Enumm1.Insider(), p = 0)
+  defaultParamNotPDT(Enumm.Enumm1)(Enumm.Enumm1.Insider())
+  pathDependentTypeDefaultParamOwnList(Enumm.Enumm1)(Enumm.Enumm1.Insider())()
+  pathDependentTypeDefaultParamOwnList(Enumm.Enumm1)(Enumm.Enumm1.Insider())(p = 0)