vim-patch:9.1.0984: exception handling can be improved

Problem:  exception handling can be improved
Solution: add v:stacktrace and getstacktrace()

closes: vim/vim#16360

663d18d610

Co-authored-by: ichizok <gclient.gaap@gmail.com>
Co-authored-by: Naruhiko Nishino <naru123456789@gmail.com>

src/nvim/eval.lua

@@ -4670,6 +4670,25 @@ M.funcs = {
     returns = 'vim.fn.getscriptinfo.ret[]',
     signature = 'getscriptinfo([{opts}])',
   },
+  getstacktrace = {
+    args = 0,
+    desc = [=[
+      Returns the current stack trace of Vim scripts.
+      Stack trace is a |List|, of which each item is a |Dictionary|
+      with the following items:
+          funcref	The funcref if the stack is at the function,
+      		otherwise this item is not exist.
+          event	The string of the event description if the
+      		stack is at autocmd event, otherwise this item
+      		is not exist.
+          lnum	The line number of the script on the stack.
+          filepath	The file path of the script on the stack.
+    ]=],
+    name = 'getstacktrace',
+    params = {},
+    returns = 'table[]',
+    signature = 'getstacktrace()',
+  },
   gettabinfo = {
     args = { 0, 1 },
     base = 1,