Problem:
Strange failure only in macos 14 CI

    FAILED   test/functional/lua/watch_spec.lua @ 82: vim._watch watchdirs() detects file changes
    test/functional/lua/watch_spec.lua:149: Expected objects to be the same.
    Passed in:
    (table: 0x0116023758) {
     *[1] = {
        [change_type] = 3
       *[path] = '/Users/runner/work/neovim/neovim/build/Xtest_tmpdir/nvim_KFMvPbXk9a/nvim_KFMvPbXk9a' }
      [2] = {
        [change_type] = 3
        [path] = '/Users/runner/work/neovim/neovim/build/Xtest_tmpdir/nvim_KFMvPbXk9a/file' } }
    Expected:
    (table: 0x010d9d6548) {
     *[1] = {
        [change_type] = 1
       *[path] = '/Users/runner/work/neovim/neovim/build/Xtest_tmpdir/nvim_KFMvPbXk9a/file' }
      [2] = {
        [change_type] = 3
        [path] = '/Users/runner/work/neovim/neovim/build/Xtest_tmpdir/nvim_KFMvPbXk9a/file' } }

    stack traceback:
            test/functional/lua/watch_spec.lua:149: in function <test/functional/lua/watch_spec.lua:82>

Solution:
Skip test for that exact version.

Problem:
The `_watch.watch()` strategy may fail if the given path does not exist:

    …/vim/_watch.lua:101: ENOENT: no such file or directory
    stack traceback:
        [C]: in function 'assert'
        …/vim/_watch.lua:101: in function <…/vim/_watch.lua:61>
        [string "<nvim>"]:5: in main chunk

- `_watch.watch()` actively asserts any error returned by `handle:start()`.
- whereas `_watch.watchdirs()` just ignores the result of `root_handle:start()`.

Servers may send "client/registerCapability" with "workspace/didChangeWatchedFiles"
item(s) (`baseUri`) which do not actually exist on the filesystem:
https://github.com/neovim/neovim/issues/28058#issuecomment-2189929424

    {
      method = "client/registerCapability",
      params = {
        registrations = { {
            method = "workspace/didChangeWatchedFiles",
            registerOptions = {
              watchers = { {
                  globPattern = {
                    baseUri = "file:///Users/does/not/exist",
                    pattern = "**/*.{ts,js,mts,mjs,cjs,cts,json,svelte}"
                  }
                },
    ...
    }

Solution:
- Remove the assert in `_watch.watch()`.
- Show a once-only message for both cases.
- More detailed logging is blocked until we have `nvim_log` / `vim.log`.

fix #28058

Problem:
137f98cf6428 added the `create` parameter to `tmpname()` but didn't
fully implement it.

Solution:
- Update impl for the `os.tmpname()` codepath.
- Inspect all usages of `tmpname()`, update various tests.

This patch replaces fswatch with inotifywait from inotify-toools:

https://github.com/inotify-tools/inotify-tools

fswatch takes ~1min to set up recursively for the Samba source code
directory. inotifywait needs less than a second to do the same thing.

https://github.com/emcrisostomo/fswatch/issues/321

Also it fswatch seems to be unmaintained in the meantime.

Signed-off-by: Andreas Schneider <asn@cryptomilk.org>

Specifically, functions that are run in the context of the test runner
are put in module `test/testutil.lua` while the functions that are run
in the context of the test session are put in
`test/functional/testnvim.lua`.

Closes https://github.com/neovim/neovim/issues/27004.

Work on https://github.com/neovim/neovim/issues/27004.