Revert changes to ExpandSAMs

They amounted to a double change owner operation

Author: odersky

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

@@ -157,15 +157,15 @@ class ExpandSAMs extends MiniPhase:
         cpy.CaseDef(cdef)(body = tru).changeOwner(anonSym, isDefinedAtFn)
       val paramRef = paramRefss.head.head
       val defaultValue = Literal(Constant(false))
-      translateMatch(pfRHS.changeOwner(anonSym, isDefinedAtFn), paramRef.symbol, pfRHS.cases.map(translateCase), defaultValue)
+      translateMatch(pfRHS, paramRef.symbol, pfRHS.cases.map(translateCase), defaultValue)
     }
 
     def applyOrElseRhs(paramRefss: List[List[Tree]])(using Context) = {
       val List(paramRef, defaultRef) = paramRefss(1)
       def translateCase(cdef: CaseDef) =
         cdef.changeOwner(anonSym, applyOrElseFn)
       val defaultValue = defaultRef.select(nme.apply).appliedTo(paramRef)
-      translateMatch(pfRHS.changeOwner(anonSym, applyOrElseFn), paramRef.symbol, pfRHS.cases.map(translateCase), defaultValue)
+      translateMatch(pfRHS, paramRef.symbol, pfRHS.cases.map(translateCase), defaultValue)
     }
 
     val constr = newConstructor(pfSym, Synthetic, Nil, Nil).entered