Remove empty saved_fresh_names map from fcode env

src/aeso_ast_to_fcode.erl

@@ -240,8 +240,7 @@ init_env(Options) ->
                       ["Chain", "GAAttachTx"]             => #con_tag{ tag = 21, arities = ChainTxArities }
                      },
        options   => Options,
-       functions         => #{},
-       saved_fresh_names => #{}
+       functions => #{}
     }.
 
 -spec builtins() -> builtins().