fix(input): fix clearing of reg_executing

vim-patch:8.2.4705

src/nvim/ex_docmd.h

@@ -29,6 +29,7 @@ typedef struct {
   bool save_finish_op;
   long save_opcount;
   int save_reg_executing;
+  bool save_pending_end_reg_executing;
   tasave_T tabuf;
 } save_state_T;