patch 8.1.1727: code for viminfo support is spread out

Problem:    Code for viminfo support is spread out.
Solution:   Move to code to viminfo.c. (Yegappan Lakshmanan, closes #4686)
diff --git a/src/proto/buffer.pro b/src/proto/buffer.pro
index 010be9c..d85a9ff 100644
--- a/src/proto/buffer.pro
+++ b/src/proto/buffer.pro
@@ -27,6 +27,7 @@
 int ExpandBufnames(char_u *pat, int *num_file, char_u ***file, int options);
 buf_T *buflist_findnr(int nr);
 char_u *buflist_nr2name(int n, int fullname, int helptail);
+void buflist_setfpos(buf_T *buf, win_T *win, linenr_T lnum, colnr_T col, int copy_options);
 void get_winopts(buf_T *buf);
 pos_T *buflist_findfpos(buf_T *buf);
 linenr_T buflist_findlnum(buf_T *buf);
@@ -55,8 +56,6 @@
 void do_arg_all(int count, int forceit, int keep_tabs);
 void ex_buffer_all(exarg_T *eap);
 void do_modelines(int flags);
-int read_viminfo_bufferlist(vir_T *virp, int writing);
-void write_viminfo_bufferlist(FILE *fp);
 int bt_normal(buf_T *buf);
 int bt_quickfix(buf_T *buf);
 int bt_terminal(buf_T *buf);