vim-patch:8.0.1562: the terminal debugger can't set a breakpoint with the mouse (#19234)

Problem:    The terminal debugger can't set a breakpoint with the mouse.
Solution:   Add popup menu entries.
71137fed4d

This ports missing popup menu code to termdebug plugin.
Despite the commit message, the code is copied from latest Vim.
WinBar code is commented out and WinBar docs is not ported.

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

@@ -37,7 +37,7 @@
 "
 " For neovim compatibility, the vim specific calls were replaced with neovim
 " specific calls:
-"   term_start -> term_open
+"   term_start -> termopen
 "   term_sendkeys -> chansend
 "   term_getline -> getbufline
 "   job_info && term_getjob -> using linux command ps to get the tty
@@ -902,6 +902,26 @@ func s:InstallCommands()
     nnoremap K :Evaluate<CR>
   endif
 
+  if has('menu') && &mouse != ''
+    call s:InstallWinbar()
+
+    let popup = 1
+    if exists('g:termdebug_config')
+      let popup = get(g:termdebug_config, 'popup', 1)
+    elseif exists('g:termdebug_popup')
+      let popup = g:termdebug_popup
+    endif
+    if popup
+      let s:saved_mousemodel = &mousemodel
+      let &mousemodel = 'popup_setpos'
+      an 1.200 PopUp.-SEP3-	<Nop>
+      an 1.210 PopUp.Set\ breakpoint	:Break<CR>
+      an 1.220 PopUp.Clear\ breakpoint	:Clear<CR>
+      an 1.230 PopUp.Run\ until		:Until<CR>
+      an 1.240 PopUp.Evaluate		:Evaluate<CR>
+    endif
+  endif
+
   let &cpo = save_cpo
 endfunc
 
@@ -956,6 +976,33 @@ func s:DeleteCommands()
     unlet s:k_map_saved
   endif
 
+  if has('menu')
+    " Remove the WinBar entries from all windows where it was added.
+    " let curwinid = win_getid(winnr())
+    " for winid in s:winbar_winids
+    "   if win_gotoid(winid)
+    "     aunmenu WinBar.Step
+    "     aunmenu WinBar.Next
+    "     aunmenu WinBar.Finish
+    "     aunmenu WinBar.Cont
+    "     aunmenu WinBar.Stop
+    "     aunmenu WinBar.Eval
+    "   endif
+    " endfor
+    " call win_gotoid(curwinid)
+    " let s:winbar_winids = []
+
+    if exists('s:saved_mousemodel')
+      let &mousemodel = s:saved_mousemodel
+      unlet s:saved_mousemodel
+      aunmenu PopUp.-SEP3-
+      aunmenu PopUp.Set\ breakpoint
+      aunmenu PopUp.Clear\ breakpoint
+      aunmenu PopUp.Run\ until
+      aunmenu PopUp.Evaluate
+    endif
+  endif
+
   call sign_unplace('TermDebug')
   unlet s:breakpoints
   unlet s:breakpoint_locations