Make ErrorKind into enum

Author: anatoliykmetyuk

library/src/scala/compiletime/testing/ErrorKind.scala

@@ -1,7 +1,5 @@
 package scala.compiletime.testing
 
 /** An error can be either a parse-time or a typecheck-time */
-sealed trait ErrorKind  // TODO make this enum, so far not doable because ScalaJS compilation fails on it
-object ErrorKind:
-  case object Parser extends ErrorKind
-  case object Typer extends ErrorKind
+enum ErrorKind:
+  case Parser, Typer