Even when at curly braces, otherwise the parser can get stuck.
This has happened in the past in #18625, but it was just worked around instead of handling the root of the problem. Now this happened again in #20171. IMO we can't let `err_and_bump()` not bump, that's too confusing and invites errors. We can (as I did) workaround the worse recovery instead.
This makes code more readale and concise,
moving all format arguments like `format!("{}", foo)`
into the more compact `format!("{foo}")` form.
The change was automatically created with, so there are far less change
of an accidental typo.
```
cargo clippy --fix -- -A clippy::all -W clippy::uninlined_format_args
```
The general theme of this is to make parser a better independent
library.
The specific thing we do here is replacing callback based TreeSink with
a data structure. That is, rather than calling user-provided tree
construction methods, the parser now spits out a very bare-bones tree,
effectively a log of a DFS traversal.
This makes the parser usable without any *specifc* tree sink, and allows
us to, eg, move tests into this crate.
Now, it's also true that this is a distinction without a difference, as
the old and the new interface are equivalent in expressiveness. Still,
this new thing seems somewhat simpler. But yeah, I admit I don't have a
suuper strong motivation here, just a hunch that this is better.
Previously we swapped to events in the buffer, but that might be wrong
if there aer `forward_parent` links pointing to the swapped-out node.
Let's do the same via parent links instead, keeping the nodes in place
