Closes https://github.com/zed-industries/zed/issues/64444

Ensures that with `ITERATIONS=200000 OPERATIONS=30`, each of the
following tests pass: `test_random_inlays`, `test_random_folds`,
`test_random_tabs`, `test_random_wraps`, `test_random_display_map`,
`test_random_blocks`, and 12/14 shards of the diff test.

Each comment contains the bug and the fix explanation.

Release Notes:

- N/A