This new package provides an API that is easier to use right than
our `*-change-functions` hooks.

The patch includes changes to `diff-mode.el` and `eglot.el` to
make use of this new package.

* lisp/emacs-lisp/track-changes.el: New file.
* test/lisp/emacs-lisp/track-changes-tests.el: New file.
* doc/lispref/text.texi (Tracking changes): New subsection.

* lisp/progmodes/eglot.el: Require `track-changes`.
(eglot--virtual-pos-to-lsp-position): New function.
(eglot--track-changes): New var.
(eglot--managed-mode): Use `track-changes-register` i.s.o
`after/before-change-functions` when available.
(eglot--track-changes-signal): New function, partly extracted from
`eglot--after-change`.
(eglot--after-change): Use it.
(eglot--track-changes-fetch): New function.
(eglot--signal-textDocument/didChange): Use it.

* lisp/vc/diff-mode.el: Require `track-changes`.
Also require `easy-mmode` before the `eval-when-compile`s.
(diff-unhandled-changes): Delete variable.
(diff-after-change-function): Delete function.
(diff--track-changes-function): Rename from `diff-post-command-hook`
and adjust to new calling convention.
(diff--track-changes): New variable.
(diff--track-changes-signal): New function.
(diff-mode, diff-minor-mode): Use it with `track-changes-register`.

* lisp/emacs-lisp/cl-extra.el (cl--describe-class-slots): Use the empty
string for the trivial `t` type.

* lisp/emacs-lisp/cl-preloaded.el (cl-structure-class):
Fix non-existing `bool` => `boolean`.

* lisp/progmodes/rust-ts-mode.el (rust-ts-flymake-command):
New option (bug#70260).
(rust-ts--flymake-proc): New variable.
(rust-ts-flymake--helper): New function.
(rust-ts-flymake): New function.
(rust-ts-mode): Add it to flymake-diagnostic-functions.

Change the handling of the old X11 convention that uses mouse-4/5/6/7
events to represent wheel events: instead of asking downstream
packages to use the `mouse-wheel-*-event` variables to know which events
represent wheel events, use new var `mouse-wheel-buttons` to directly
convert those events into the standard `wheel-up/down/left/right` events
used everywhere else.

This will simplify the work of packages which can thus just bind their
commands to `wheel-up/down/left/right`.

* lisp/mouse.el (mouse-wheel-buttons): New custom variable.

* src/keyboard.c (make_lispy_event): Adjust for "wheel-clicks" on the tab-bar.
* src/xterm.c (x_construct_mouse_click): Add `xi2` argument and
obey `mouse-wheel-buttons` variable.
(handle_one_xevent): Adjust calls accordingly.
(syms_of_xterm): Define the `mouse-wheel-buttons` and the
`wheel-up/down/left/right`symbols.

* lisp/xt-mouse.el: Don't require `mwheel` any more.
(xterm-mouse--same-button-p): Delete function.
(xterm-mouse--read-event-sequence): Use `mouse-wheel-buttons`.

* lisp/mwheel.el (mouse-wheel-up-event, mouse-wheel-down-event)
(mouse-wheel-left-event, mouse-wheel-right-event): Make obsolete.
(mouse-wheel-obey-old-style-wheel-buttons): Delete variable.

* lisp/completion-preview.el (completion-preview--mouse-map):
* lisp/progmodes/flymake.el (flymake--mode-line-counter-map):
* lisp/edmacro.el (edmacro-fix-menu-commands): Silence warnings.

* lisp/textmodes/reftex-parse.el (reftex-move-to-previous-arg):
Recognize ')' as closing delimiter for optional argument.
Fix docstring.
(reftex-what-macro): Identify LaTeX macros with optional arguments
in parentheses correctly.  This is necessary to make
`reftex-view-crossref' work with biblatex on entries like:
\parencites(Glob.Pre)(Glob.Post)[Pre][Post]{key1}[Pre][Post]{key2}
(bug#31132)

Add a hack to prevent flymake from complaining about a missing lexical
cookie when enabled in *scratch*.

* lisp/emacs-lisp/bytecomp.el
(bytecomp--inhibit-lexical-cookie-warning): New variable.
(byte-compile-file): Use it to gate the warning.
* lisp/progmodes/elisp-mode.el (elisp-flymake-byte-compile):
Set the inhibitor when spawning a check in lisp-interaction-mode.

* lisp/dired.el (dired-insert-directory): Insert leading space
if absent before calling dired-align-file.

* lisp/window.el (window-point-context-set)
(window-point-context-use): Add 'window-buffer' for 'buffer-name'.