vim-patch:8.2.2070: can't get the exit value in VimLeave(Pre) autocommands (#13981)

Problem:    Can't get the exit value in VimLeave or VimLeavePre autocommands.
Solution:   Add v:exiting like in Neovim. (Yegappan Lakshmanan, closes vim/vim#7395)
https://github.com/vim/vim/commit/f0068c5154a99b86b2c4515a4b93c003b2445cf4

Rearrange VimVarIndex enums and vimvars[] entries to sync with  Vim.

N/A patches for version.c:

vim-patch:8.2.2535: MS-Windows: cannot run all vim9 tests

Problem:    MS-Windows: cannot run all vim9 tests.
Solution:   Make test_vim9 target work.
https://github.com/vim/vim/commit/723ef5db980b2e69ef8bdc0dd448cb645491c464

1 files changed, 29 insertions, 0 deletions

diff --git a/src/nvim/testdir/test_exit.vim b/src/nvim/testdir/test_exit.vim
index 99a401d4a4..bd3e9eb4d4 100644
--- a/src/nvim/testdir/test_exit.vim
+++ b/src/nvim/testdir/test_exit.vim
@@ -81,3 +81,32 @@ func Test_exiting()
   endif
   call delete('Xtestout')
 endfunc
+
+" Test for getting the Vim exit code from v:exiting
+func Test_exit_code()
+  call assert_equal(v:null, v:exiting)
+
+  let before =<< trim [CODE]
+    au QuitPre * call writefile(['qp = ' .. v:exiting], 'Xtestout', 'a')
+    au ExitPre * call writefile(['ep = ' .. v:exiting], 'Xtestout', 'a')
+    au VimLeavePre * call writefile(['lp = ' .. v:exiting], 'Xtestout', 'a')
+    au VimLeave * call writefile(['l = ' .. v:exiting], 'Xtestout', 'a')
+  [CODE]
+
+  if RunVim(before, ['quit'], '')
+    call assert_equal(['qp = null', 'ep = null', 'lp = 0', 'l = 0'], readfile('Xtestout'))
+  endif
+  call delete('Xtestout')
+
+  if RunVim(before, ['cquit'], '')
+    call assert_equal(['lp = 1', 'l = 1'], readfile('Xtestout'))
+  endif
+  call delete('Xtestout')
+
+  if RunVim(before, ['cquit 4'], '')
+    call assert_equal(['lp = 4', 'l = 4'], readfile('Xtestout'))
+  endif
+  call delete('Xtestout')
+endfunc
+
+" vim: shiftwidth=2 sts=2 expandtab