Problem:
nvim_create_autocmd() isn't |api-fast|, so modules that create autocmds
(e.g. vim.treesitter.query) can't be require()d in a fast event context.
Solution:
Mark it |api-fast|. Compile autocmd patterns with RE_NOBREAK so
aucmd_next() won't os_breakcheck() mid-iteration, where a fast
nvim_create_autocmd() could realloc the autocmds vector and dangle the
caller's AutoPat/AutoCmd.
RE_NOBREAK is low-risk because:
- aucmd_next()'s loop checks CTRL-C: `(for (… i < apc->ausize && !got_int; …)`.
- `line_breakcheck()` (`autocmd.c:1912`) runs once per matched autocmd.
- Each autocmd _execution_ runs through `do_cmdline`, which has its own
breakchecks.
However this does admit risk of a pathological case:
a catastrophic-backtracking glob matched against a very long `User`
event-pattern.
Co-authored-by: Riley Bruins <ribru17@hotmail.com>
Co-authored-by: zeertzjq <zeertzjq@outlook.com>
