fix: reversed wconf parsing order to mirror scala 2

Author: johnmatthiggins

Diff for: compiler/src/dotty/tools/dotc/reporting/WConf.scala

@@ -91,7 +91,7 @@ object WConf:
     val setting = ctx.settings.Wconf.value
     def cached = ctx.base.wConfCache
     if cached == null || cached._1 != setting then
-      val conf = fromSettings(setting)
+      val conf = fromSettings(setting.reverse)
       ctx.base.wConfCache = (setting, conf.getOrElse(WConf(Nil)))
       conf.swap.foreach(msgs =>
         val multiHelp =