fix(tvix/eval): always add history entries in REPL

... even if the code is broken.

Change-Id: I5898bceaebf201b97e8988c94c90e7fafff82529
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6462
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>

tvix/eval/src/main.rs

@@ -62,10 +62,10 @@ fn run_prompt() {
                     continue;
                 }
 
+                rl.add_history_entry(&line);
                 match tvix_eval::interpret(&line, None) {
                     Ok(result) => {
                         println!("=> {} :: {}", result, result.type_of());
-                        rl.add_history_entry(line);
                     }
                     Err(err) => println!("{}", err),
                 }