Allow "-" when back-translating

Author: geo2a

kore/src/Kore/Rewrite/SMT/Translate.hs

@@ -563,8 +563,11 @@ backTranslateWith
                 . Map.map AST.symbolData
                 $ Map.filter (not . isBuiltin . AST.symbolDeclaration) symbols
 
-        isBuiltin :: AST.KoreSymbolDeclaration a b -> Bool
-        isBuiltin AST.SymbolBuiltin{} = True
+        isBuiltin :: AST.KoreSymbolDeclaration SExpr SExpr -> Bool
+        isBuiltin (AST.SymbolBuiltin (AST.IndirectSymbolDeclaration{name})) =
+            case name of
+                Atom "-" -> False
+                _ -> True
         isBuiltin _other = False
 
         symbolFrom :: Id -> Symbol