vim-patch:8.1.2341: not so easy to interrupt a script programatically

Problem:    Not so easy to interrupt a script programatically.
Solution:   Add the interrupt() function. (Yasuhiro Matsumoto, closes vim/vim#2834)
67a2deb9cb

src/nvim/eval.lua

@@ -191,6 +191,7 @@ return {
     inputsave={},
     inputsecret={args={1, 2}},
     insert={args={2, 3}},
+    interrupt={args=0},
     invert={args=1},
     isdirectory={args=1},
     isinf={args=1},