patch 8.0.0457: using :move messes up manual folds

Problem:    Using :move messes up manual folds.
Solution:   Split adjusting marks and folds.  Add foldMoveRange(). (neovim
            patch #6221)
diff --git a/src/proto/mark.pro b/src/proto/mark.pro
index 90be1a5..ff1f441 100644
--- a/src/proto/mark.pro
+++ b/src/proto/mark.pro
@@ -19,6 +19,7 @@
 void ex_clearjumps(exarg_T *eap);
 void ex_changes(exarg_T *eap);
 void mark_adjust(linenr_T line1, linenr_T line2, long amount, long amount_after);
+void mark_adjust_nofold(linenr_T line1, linenr_T line2, long amount, long amount_after);
 void mark_col_adjust(linenr_T lnum, colnr_T mincol, long lnum_amount, long col_amount);
 void copy_jumplist(win_T *from, win_T *to);
 void free_jumplist(win_T *wp);