There is a comment on the badness in the test

https://github.com/paulp/scala/blob/d3e24c95103f204fc1f8255f2db57e4b2a0d0d2a/test/files/neg/t5702-neg-bad-brace.scala#L8

```
// the erroneous brace is ignored, so we can't halt on it.
// maybe brace healing can detect overlapping unmatched (...}
// In this case, the fix emits an extra error:
// t5702-neg-bad-brace.scala:10: error: Unmatched closing brace '}' ignored here
// t5702-neg-bad-brace.scala:10: error: illegal start of simple pattern (i.e., =>)
// t5702-neg-bad-brace.scala:11: error: ')' expected but '}' found.
```
Too bad I left stale comments in the test source.