fix(treesitter): improve vim.treesitter.foldexpr

* Collect on_bytes and flush at the invocation of the scheduled callback
  to take account of commands that triggers multiple on_bytes.
* More accurately track movement of folds so that foldexpr returns
  reasonable values even when the scheduled computation is not run yet.
* Start computing folds from the line above (+ foldminlines) the changed
  lines to handle the folds that are removed due to the size limit.
* Shrink folds that end at the line at which another fold starts to
  assign proper level to that line.
* Use level '=' for lines that are not computed yet.

0 files changed, 0 insertions, 0 deletions