bug#70396: 30.0.50; Eglot, rust-analyzer buffer formatting, and track changes errors

[Stefan Monnier]

> When formatting a specific rust file with with `eglot-format-buffer`
> (rust-analyzer LSP), I'm getting:
>
> * Track changes errors (below).
> * An `args-out-of-range` error in `replace-buffer-contents`.
>
> To reproduce:
>
> 1. Checkout `https://github.com/Stebalien/xattr/`. I can try for a
>    minimal reproducer if necessary.
> 2. Install rust-analyzer.
> 2. Run `emacs -Q`
> 3. `M-x find-file "src/sys/linux_macos.rs"`
>    (https://github.com/Stebalien/xattr/blob/master/src/sys/linux_macos.rs).
> 4. `M-x rust-ts-mode`
> 5. `M-x eglot`
> 6. `M-x eglot-format-buffer`

Thanks for the nice bug report.
Will look into it ASAP,


        Stefan