Jörg Bornemann authored Jan 25, 2024 and Brad King committed Jan 25, 2024

This change was spawned by the desire to use `narrow-to-defun` in CMake
files. However, there was no "CMake version" of that function, and it
turns out that we don't need one if we make `beginning-of-defun` and
`end-of-defun` work in `cmake-mode`.

In the setup code of `cmake-mode` we now set the local variables
`beginning-of-defun-function` and `end-of-defun-function`. This makes
`beginning-of-defun` and `end-of-defun` work as expected.

Functions that use this facility also work now: `mark-defun` and
`narrow-to-defun` and possibly others.

We remove `cmake-mark-defun` since it's superfluous now.

We remove the defun-related key bindings since the standard functions
that are bound globally work fine with this patch.