build: auto-generate syntax lists

Changes:

* Use the commands from contrib/vim/syntax/firejail.vim to create
  makefile targets to generate syntax lists in contrib/syntax/lists
* Add contrib/syntax/files/example.in as an example of how to generate
  syntax files
* Generate and add the syntax lists, to make it easier to spot if they
  are properly updated when a new command is added or if their recipes
  also need changes
* Add "syntax" and "contrib" makefile targets

Note: The generation commands are executed mostly silently to avoid
generating too much noise when also making other targets.

Note2: In some generation commands, a `$$` escape is used to pass `$` to
the shell, to avoid being interpreted by make as the start of a macro.

Note3: `@make_input@` is used in example.in to make it clear that the
file is generated (and that it is generated by make rather than
configure), similarly to how `@configure_input@` is used in configure
input files.  See also apparmor.vim:

    $ head -n 2 /usr/share/vim/vimfiles/syntax/apparmor.vim
    " generated from apparmor.vim.in by create-apparmor.vim.py
    " do not edit this file - edit apparmor.vim.in or create-apparmor.vim.py instead

Environment: apparmor 3.1.2-1 on Artix Linux.

Relates to #2679 #5502 #5577 #5612.

1 files changed, 29 insertions, 0 deletions

diff --git a/contrib/syntax/lists/syscall_groups.list b/contrib/syntax/lists/syscall_groups.list
new file mode 100644
index 000000000..fb42ae5f7
--- /dev/null
+++ b/contrib/syntax/lists/syscall_groups.list
@@ -0,0 +1,29 @@
+aio
+basic-io
+chown
+clock
+cpu-emulation
+debug
+default
+default-keep
+default-nodebuggers
+file-system
+io-event
+ipc
+keyring
+memlock
+module
+mount
+network-io
+obsolete
+privileged
+process
+raw-io
+reboot
+resources
+setuid
+signal
+swap
+sync
+system-service
+timer