fixes #25043: js tyUserTypeClass internal error (#25044)

- **fixes #25043: `internal error: genTypeInfo(tyUserTypeClassInst)`**
- **chore(test): for 25043**

(cherry picked from commit 7e2df41850)

compiler/jstypes.nim

@@ -122,7 +122,7 @@ proc genEnumInfo(p: PProc, typ: PType, name: Rope) =
          [name, genTypeInfo(p, typ.baseClass)])
 
 proc genTypeInfo(p: PProc, typ: PType): Rope =
-  let t = typ.skipTypes({tyGenericInst, tyDistinct, tyAlias, tySink, tyOwned})
+  let t = typ.skipTypes({tyGenericInst, tyDistinct, tyAlias, tySink, tyOwned} + tyUserTypeClasses)
   result = "NTI$1" % [rope(t.id)]
   if containsOrIncl(p.g.typeInfoGenerated, t.id): return
   case t.kind

tests/js/t25043.nim

@@ -0,0 +1,15 @@
+discard """
+  action: "compile"
+"""
+
+proc audit*(event: string, args: varargs[string]) = discard
+# args is `varargs[Any]` in real world code
+
+type PathLike[T] = concept self
+  $self is T  # a simplified definition
+
+proc utime[T](path: PathLike[T]) =
+  audit("os.utime", $path)
+
+when isMainModule:
+  utime("sad")