patch 8.2.4001: insert complete code uses global variables

Problem:    Insert complete code uses global variables.
Solution:   Make variables local to the file and use accessor functions.
            (Yegappan Lakshmanan, closes #9470)
diff --git a/src/proto/insexpand.pro b/src/proto/insexpand.pro
index 6d97557..c9183bb 100644
--- a/src/proto/insexpand.pro
+++ b/src/proto/insexpand.pro
@@ -17,6 +17,10 @@
 int ctrl_x_mode_line_or_eval(void);
 int ctrl_x_mode_not_default(void);
 int ctrl_x_mode_not_defined_yet(void);
+int compl_status_adding(void);
+int compl_status_sol(void);
+int compl_status_local(void);
+void compl_status_clear(void);
 int has_compl_option(int dict_opt);
 int vim_is_ctrl_x_key(int c);
 int ins_compl_accept_char(int c);
@@ -35,6 +39,7 @@
 int ins_compl_interrupted(void);
 int ins_compl_enter_selects(void);
 colnr_T ins_compl_col(void);
+int ins_compl_len(void);
 int ins_compl_bs(void);
 void ins_compl_addleader(int c);
 void ins_compl_addfrommatch(void);
@@ -45,7 +50,6 @@
 void set_buflocal_ofu_callback(buf_T *buf);
 int set_thesaurusfunc_option(void);
 int set_ref_in_insexpand_funcs(int copyID);
-callback_T *get_insert_callback(int type);
 void f_complete(typval_T *argvars, typval_T *rettv);
 void f_complete_add(typval_T *argvars, typval_T *rettv);
 void f_complete_check(typval_T *argvars, typval_T *rettv);