vim-patch:9.1.0697: [security]: heap-buffer-overflow in ins_typebuf (#37372)

Problem:  heap-buffer-overflow in ins_typebuf
          (SuyueGuo)
Solution: When flushing the typeahead buffer, validate that there
          is enough space left

Github Advisory:
https://github.com/vim/vim/security/advisories/GHSA-4ghr-c62x-cqfh

322ba91086

Co-authored-by: Christian Brabandt <cb@256bit.org>

test/old/testdir/test_crash.vim

@@ -220,6 +220,13 @@ func Test_crash1_3()
   call term_sendkeys(buf, args)
   call TermWait(buf, 150)
 
+  let file = 'crash/heap_overflow3'
+  let cmn_args = "%s -u NONE -i NONE -n -X -m -n -e -s -S %s -c ':qa!'"
+  let args = printf(cmn_args, vim, file)
+  call term_sendkeys(buf, args)
+  call TermWait(buf, 150)
+
+
   " clean up
   exe buf .. "bw!"
   bw!