vim-patch:fce324f557: runtime(termdebug): close all buffers in the same way

For ASM and Variables buffer, check were done to make sure they existed
before attempting to close them, but not for debugged program or gdb
communication. The debugged program window is a user-facing one and
user might close it manually, so it's better to check if it exists.

https://github.com/vim/vim/commit/fce324f55718192ae7de389bb88d423eed7977a2

Co-authored-by: Damien Riegel <damien@riegel.io>
AI-assisted: Codex

runtime/pack/dist/opt/termdebug/plugin/termdebug.vim

@@ -227,12 +227,16 @@ endfunc
 
 " Use when debugger didn't start or ended.
 func s:CloseBuffers()
-  exe $'bwipe! {s:ptybufnr}'
-  if s:asmbufnr > 0 && bufexists(s:asmbufnr)
-    exe $'bwipe! {s:asmbufnr}'
-  endif
-  if s:varbufnr > 0 && bufexists(s:varbufnr)
-    exe $'bwipe! {s:varbufnr}'
+  for bufnr in [get(s:, 'ptybufnr', 0), get(s:, 'asmbufnr', 0), get(s:, 'varbufnr', 0)]
+    if bufnr > 0 && bufexists(bufnr)
+      execute $'bwipe! {bufnr}'
+    endif
+  endfor
+  if exists('s:comm_job_id')
+    let commbufnr = get(nvim_get_chan_info(s:comm_job_id), 'buffer', 0)
+    if commbufnr > 0 && bufexists(commbufnr)
+      execute $'bwipe! {commbufnr}'
+    endif
   endif
   let s:running = v:false
   unlet! s:gdbwin