vim-patch:8.2.2704: adding a lot of completions can be a bit slow

Problem:    Adding a lot of completions can be a bit slow.
Solution:   Use fast_breakcheck() instead of ui_breakcheck() when adding a
            list of completions. (Ben Jackson, closes vim/vim#8061)
440cf096fa

src/nvim/edit.h

@@ -19,6 +19,7 @@ typedef enum {
   CP_CONT_S_IPOS = 4,    // use CONT_S_IPOS for compl_cont_status
   CP_EQUAL = 8,          // ins_compl_equal() always returns true
   CP_ICASE = 16,         // ins_compl_equal ignores case
+  CP_FAST = 32,          // use fast_breakcheck instead of ui_breakcheck
 } cp_flags_T;
 
 typedef int (*IndentGetter)(void);