Problem:
If an edit cascades to cursor(s) that happen to be within a closed fold,
the edit acts on the fold itself (`:h fold-behavior`). E.g. "dd" deletes
the entire fold, not the cursor's line within the fold.
Solution:
Check `mc_replaying()` in `hasAnyFolding()`, so folds are ignored during
a multicursor cascade. This means multicursor always replays relative to
text *within* the fold.
350fa5ad7c