runtime(vim): Update base-syntax, fix escaping :syn and :hi sub-groups (#14137)

* runtime(vim): Update base-syntax, fix escaping :syn and :hi sub-groups

- Remove contained :syntax and :highlight sub-groups from the function
  body cluster.  These should only match in the respective commands.
- Remove vimSynLine syntax group from several clusters.  The definition
  of vimSynLine was removed in Vim 5.3.

* runtime(vim): Update syntax generator, use standard Last Change date format

The de facto standard date format is YYYY MMM DD.

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

runtime/syntax/testdir/input/vim_ex_syntax.vim

@@ -0,0 +1,177 @@
+" Vim :syntax command
+
+syn match testMatch "pattern" contained " tail comment
+" NOTE: comments not currently supported
+syn keyword testKeyword keyword contained " tail comment
+syn region testRegion start="start-pattern" skip="skip-pattern" end="end-pattern" contained " tail comment
+
+" Multiline commands
+
+syn keyword testKeyword
+      "\ OPTIONS
+      "\ conceal option
+      \ conceal
+      "\ cchar option
+      \ cchar=&
+      "\ contained option
+      \ contained
+      "\ containedin option
+      \ containedin=testContainer
+      "\ nextgroup option
+      \ nextgroup=testNext0,@testCluster
+      "\ transparent option
+      \ transparent
+      "\ skipwhite option
+      \ skipwhite
+      "\ skipempty option
+      \ skipempty
+      "\ skipnl option
+      \ skipnl
+      "\ KEYWORDS LIST
+      "\ keyword 1
+      \ keyword1
+      "\ keyword 2
+      \ keyword2
+      "\ keyword 3
+      \ keyword3
+
+syn match testMatch
+      "\ MATCH PATTERN
+      "\ pattern start
+      \ /
+      "\ part 1 description
+      \pat1a .* pat1b
+      "\ part 2 description
+      \pat2a .* pat2b
+      "\ part 3 description
+      \pat3a .* pat3b
+      "\ pattern end
+      \/
+      "\ OPTIONS
+      "\ conceal option
+      \ conceal
+      "\ cchar option
+      \ cchar=&
+      "\ contained option
+      \ contained
+      "\ containedin option
+      \ containedin=testContainer
+      "\ nextgroup option
+      \ nextgroup=testNext0,@testCluster
+      "\ transparent option
+      \ transparent
+      "\ skipwhite option
+      \ skipwhite
+      "\ skipempty option
+      \ skipempty
+      "\ skipnl option
+      \ skipnl
+      "\ contains option
+      \ contains=testContained1,testContained2
+      "\ fold option
+      \ fold
+      "\ display option
+      \ display
+      "\ extend option
+      \ extend
+      "\ excludenl option
+      \ excludenl
+      "\ keepend option
+      \ keepend
+
+syn region testRegion
+      "\ OPTIONS
+      "\ start option
+      \ start="start-pattern"
+      "\ skip option
+      \ skip="skip-pattern"
+      "\ end option
+      \ end="end-pattern"
+      "\ conceal option
+      \ conceal
+      "\ cchar option
+      \ cchar=&
+      "\ contained option
+      \ contained
+      "\ containedin option
+      \ containedin=testContainer
+      "\ nextgroup option
+      \ nextgroup=testNext0,@testCluster
+      "\ transparent option
+      \ transparent
+      "\ skipwhite option
+      \ skipwhite
+      "\ skipempty option
+      \ skipempty
+      "\ skipnl option
+      \ skipnl
+      "\ contains option
+      \ contains=testContained1,testContained2
+      "\ oneline option
+      \ oneline
+      "\ fold option
+      \ fold
+      "\ display option
+      \ display
+      "\ extend option
+      \ extend
+      "\ concealends option
+      \ concealends
+      "\ excludenl option
+      \ excludenl
+      "\ keepend option
+      \ keepend
+
+syn cluster testCluster
+      "\ OPTIONS
+      "\ contains option
+      \ contains=testContained1,testContained2,testContained3
+
+syn cluster testCluster
+      "\ OPTIONS
+      "\ add option
+      \ add=testAdd
+      "\ remove option
+      \ remove=testRemove
+
+
+" multiline group list
+
+syn keyword testNext0 keyword
+syn keyword testNext1 keyword
+syn keyword testNext2 keyword
+syn keyword testNext3 keyword
+syn keyword testNext4 keyword
+syn keyword testNext5 keyword
+syn keyword testNext6 keyword
+syn keyword testNext7 keyword
+syn keyword testNext8 keyword
+syn keyword testNext9 keyword
+
+syn keyword testKeyword
+      "\ nextgroup option
+      \ nextgroup=
+      "\ a comment
+      \ testNext0 , testNext1 , 
+      "\ a comment
+      \ testNext[2-8].* , 
+      "\ a comment
+      \ testNext9 , @testCluster skipwhite
+      "\ KEYWORDS LIST
+      \ keyword4
+      \ keyword5
+      \ keyword6
+
+
+" leaking contained groups
+
+" Example: runtime/syntax/zsh.vim
+"   "cluster" should not be highlighted outside of :syntax commands
+
+function! s:ContainedGroup()
+  " ...
+  for cluster in ['markdownHighlight_zsh', 'zsh']
+    " ...
+  endfor
+  " ...
+endfunction