return simplified check

Author: Alex1005a

compiler/src/dotty/tools/dotc/typer/Typer.scala

@@ -4269,6 +4269,7 @@ class Typer(@constructorOnly nestingLevel: Int = 0) extends Namer
               def qualifying = (ownedVars -- locked).toList
               val resultAlreadyConstrained = pt1.isInstanceOf[MethodOrPoly]
               if !formal.isGround
+                && formal.simplified `ne` formal
                 && (pt1 `ne` pt)
                 && (pt1 ne sharpenedPt)
                 && (ownedVars ne locked)