runtime(vim): Update base syntax, improve function call highlighting

- Match more function calls.
- Contain function call syntax groups.
- Improve differentiation between Ex commands and builtin functions with
  the same name.  Remove special cases.  Command modifiers are not
  currently well differentiated from functions.

closes: #17712

Signed-off-by: Doug Kearns <dougkearns@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

runtime/syntax/testdir/input/vim_function_call.vim

@@ -0,0 +1,265 @@
+" Vim function calls
+" VIM_SETUP highlight link vimUserFunc Todo
+
+
+call abs(42)
+
+
+" command/function distinction
+
+" append browse call chdir confirm copy delete eval execute filter function
+" insert join map match mode sort split substitute swapname type
+
+let append = append(42)
+call append(42)
+" command
+append
+.
+" bad command
+append(42)
+append (42)
+
+let browse = browse(42)
+call browse(42)
+" command
+browse(42)
+browse (42)
+
+let call = call(42)
+call call(42)
+" command
+call(42)
+call (42)
+
+let chdir = chdir(42)
+call chdir(42)
+" command
+chdir(42)
+chdir (42)
+
+let confirm = confirm(42)
+call confirm(42)
+" command
+confirm(42)
+confirm (42)
+
+let copy = copy(42)
+call copy(42)
+" command
+copy(42)
+copy (42)
+
+let delete = delete(42)
+call delete(42)
+" command
+delete(42)
+delete (42)
+
+let eval = eval(42)
+call eval(42)
+" command
+eval(42)
+eval (42)
+
+let execute = execute(42)
+call execute(42)
+" command
+execute(42)
+execute (42)
+
+let filter = filter(42)
+call filter(42)
+" command
+filter(42)
+filter (42)
+
+let function = function(42)
+call function(42)
+" command
+function(42)
+function (42)
+
+let insert = insert(42)
+call insert(42)
+" command
+insert
+.
+" bad command
+insert(42)
+insert (42)
+
+let join = join(42)
+call join(42)
+" command
+join(42)
+join (42)
+
+let map = map(42)
+call map(42)
+" command
+map(42)
+map (42)
+
+let match = match(42)
+call match(42)
+" command
+match(42)
+match (42)
+
+let sort = sort(42)
+call sort(42)
+" command
+sort(42)
+sort (42)
+
+let split = split(42)
+call split(42)
+" command
+split(42)
+split (42)
+
+let substitute = substitute(42)
+call substitute(42)
+" command
+substitute(42)
+substitute (42)
+
+let swapname = swapname(42)
+call swapname(42)
+" command
+swapname(42)
+swapname (42)
+
+let type = type(42)
+call type(42)
+" Vim9 command
+" type(42)
+" type (42)
+
+let uniq = uniq(42)
+call uniq(42)
+" command
+uniq(42)
+uniq (42)
+
+
+" errors
+
+let foo = foo(42)
+call foo(42)
+
+let if = if(42)
+call if(42)
+" command
+if(42) | .. | endif
+if (42) | .. | endif
+
+let echo = echo(42)
+call echo(42)
+" command
+echo(42)
+echo (42)
+
+
+" expressions
+
+let foo = abs(42)
+
+echo abs(42)
+echo (abs(42))
+echo abs(42) + foo
+echo foo + abs(42)
+
+echo Foo()
+echo (Foo())
+echo Foo() + bar
+echo bar + Foo()
+
+
+" scope modifiers and qualified names
+
+let foo = s:foo(42)
+call s:foo(42)
+
+let foo = g:foo(42)
+call g:foo(42)
+
+let foo = b:foo(42)
+call b:foo(42)
+
+let foo = w:foo(42)
+call w:foo(42)
+
+let foo = t:foo(42)
+call t:foo(42)
+
+let foo = l:foo(42)
+call l:foo(42)
+
+let foo = a:foo(42)
+call a:foo(42)
+
+let foo = v:foo(42)
+call v:foo(42)
+
+
+let foo = module.foo(42)
+call module.foo(42)
+
+let foo = s:module.foo(42)
+call module.foo(42)
+
+let foo = g:module.foo(42)
+call g:module.foo(42)
+
+let foo = b:module.foo(42)
+call b:module.foo(42)
+
+let foo = w:module.foo(42)
+call w:module.foo(42)
+
+let foo = t:module.foo(42)
+call t:module.foo(42)
+
+let foo = l:module.foo(42)
+call l:module.foo(42)
+
+let foo = a:module.foo(42)
+call a:module.foo(42)
+
+let foo = v:module.foo(42)
+call v:module.foo(42)
+
+
+let foo = module#foo(42)
+call module#foo(42)
+
+let foo = g:module#foo(42)
+call g:module#foo(42)
+
+
+" not builtin functions
+
+call s:substitute()
+call g:substitute()
+call b:substitute()
+call w:substitute()
+call t:substitute()
+call l:substitute()
+call a:substitute()
+call v:substitute()
+
+call <SID>substitute()
+
+call s:substitute.substitute()
+call g:substitute.substitute()
+call b:substitute.substitute()
+call w:substitute.substitute()
+call t:substitute.substitute()
+call l:substitute.substitute()
+call a:substitute.substitute()
+call v:substitute.substitute()
+
+call substitute#substitute()
+call g:substitute#substitute()
+