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/eval.pro b/src/proto/eval.pro
index 8a19542..6f08ae7 100644
--- a/src/proto/eval.pro
+++ b/src/proto/eval.pro
@@ -126,8 +126,7 @@
 void setwinvar(typval_T *argvars, typval_T *rettv, int off);
 char_u *autoload_name(char_u *name);
 int script_autoload(char_u *name, int reload);
-int read_viminfo_varlist(vir_T *virp, int writing);
-void write_viminfo_varlist(FILE *fp);
+var_flavour_T var_flavour(char_u *varname);
 int store_session_globals(FILE *fd);
 void last_set_msg(sctx_T script_ctx);
 void reset_v_option_vars(void);