runtime(vim): Update base-syntax, improve :echo and :execute highlighting (#14199)

Improve :echo and :execute highlighting.

- Add better line-continuation support for both commands.
- Improve the :execute command's expression argument matching.
- Remove the fix for issue #9987 as this is now handled by correctly
  matching the parens in :echo (...) as operator parens.


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

runtime/syntax/testdir/input/vim_ex_echo.vim

@@ -15,6 +15,24 @@ echo "Answer = "
      "\ comment
       \ 42
 
+echo
+      \ "Answer = "
+     "\ comment
+      \ 42
+
 " :echo without {expr}
 echo| echo "Foo"
 
+" trailing comment needs |
+echo "foo" | " comment
+
+
+" Issue #9987 (parenthesised argument - not a function call)
+
+let foo = {'end': 123}
+
+if 123
+	echo (foo.end)
+else
+	echo 'bar'
+endif

runtime/syntax/testdir/input/vim_ex_execute.vim

@@ -0,0 +1,41 @@
+" Vim :execute command
+
+" :help :execute
+
+execute "buffer" nextbuf
+execute "normal" count .. "w"
+execute '!ls' | echo "theend"
+execute "normal ixxx\<Esc>"
+execute "e " .. fnameescape(filename)
+execute "!ls " .. shellescape(filename, 1)
+if 0
+ execute 'while i > 5'
+  echo "test"
+ endwhile
+endif
+execute 'while i < 5 | echo i | let i = i + 1 | endwhile'
+
+" following command is :|"
+execute "call Foo()" | |
+
+execute "call"
+      "\ comment
+      \ "Foo()"
+
+execute
+      \ "call"
+      "\ comment
+      \ "Foo()"
+
+" :execute without {expr}
+execute| echo "Foo"
+
+" trailing comment needs |
+execute "foo" | " comment
+
+
+" Issue #9987 (parenthesised argument - not a function call)
+
+" FIXME: execute is ex command not builtin function
+let foo = {'arg': "call Foo()"}
+execute (foo.arg)