epsilon functions generated with proper flags

src/main/scala/leon/xlang/EpsilonElimination.scala

@@ -30,6 +30,8 @@ object EpsilonElimination extends UnitPhase[Program] {
           }.toMap ++ Seq((epsilonVar, Variable(resId)))
           val postcondition = replace(eMap, pred)
           newFunDef.postcondition = Some(Lambda(Seq(ValDef(resId)), postcondition))
+          newFunDef.addFlags(fd.flags)
+          newFunDef.addFlag(Annotation("extern", Seq()))
           LetDef(Seq(newFunDef), FunctionInvocation(newFunDef.typed, bSeq map Variable))
 
         case (other, _) => other