Fix this type in macro

Author: nicolasstucki

compiler/src/dotty/tools/dotc/transform/PCPCheckAndHeal.scala

@@ -54,7 +54,7 @@ class PCPCheckAndHeal(@constructorOnly ictx: Context) extends TreeMapWithStages(
         else TypeTree(healedType).withSpan(tree.span)
 
       case _: This =>
-        if level != levelOf(tree.symbol) then
+        if level != -1 && level != levelOf(tree.symbol) then
           levelError(tree.symbol, tree.tpe, tree.sourcePos, "")
         tree
       case _: Ident =>