vim-patch:9.1.1077: included syntax items do not understand contains=TOP (#32343)

Problem:  Syntax engine interpreted contains=TOP as matching nothing
          inside included files, since :syn-include forces HL_CONTAINED
          on for every included item. After 8.2.2761, interprets
          contains=TOP as contains=@INCLUDED, which is also not correct
          since it doesn't respect exclusions, and doesn't work if there
          is no @INCLUDED cluster.
Solution: revert patch 8.2.2761, instead track groups that have had
          HL_CONTAINED forced, and interpret contains=TOP and
          contains=CONTAINED using this. (Theodore Dubois)

fixes: vim/vim#11277
closes: vim/vim#16571

f50d5364d7

Co-authored-by: Theodore Dubois <tblodt@icloud.com>

test/old/testdir/test_syntax.vim

@@ -944,7 +944,7 @@ func Test_syn_contained_transparent()
 endfunc
 
 func Test_syn_include_contains_TOP()
-  let l:case = "TOP in included syntax means its group list name"
+  let l:case = "TOP in included syntax refers to top level of that included syntax"
   new
   syntax include @INCLUDED syntax/c.vim
   syntax region FencedCodeBlockC start=/```c/ end=/```/ contains=@INCLUDED
@@ -959,6 +959,18 @@ func Test_syn_include_contains_TOP()
   bw!
 endfunc
 
+func Test_syn_include_contains_TOP_excluding()
+  new
+  syntax include @INCLUDED syntax/c.vim
+  syntax region FencedCodeBlockC start=/```c/ end=/```/ contains=@INCLUDED
+
+  call setline(1,  ['```c', '#if 0', 'int', '#else', 'int', '#if', '#endif', '```' ])
+  let l:expected = ["cCppOutElse", "cConditional"]
+  eval AssertHighlightGroups(6, 1, l:expected, 1)
+  syntax clear
+  bw!
+endfunc
+
 " This was using freed memory
 func Test_WinEnter_synstack_synID()
   autocmd WinEnter * call synstack(line("."), col("."))