patch 9.1.1108: 'smoothscroll' gets stuck with 'listchars' "eol"

Problem:  'smoothscroll' gets stuck with 'listchars' "eol".
Solution: Count size of 'listchars' "eol" in line size when scrolling.
          (zeertzjq)

related: neovim/neovim#32405
closes: #16627

Signed-off-by: zeertzjq <zeertzjq@outlook.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/proto/charset.pro b/src/proto/charset.pro
index 54af280..bf1fc10 100644
--- a/src/proto/charset.pro
+++ b/src/proto/charset.pro
@@ -22,6 +22,7 @@
 int linetabsize_col(int startcol, char_u *s);
 int win_linetabsize(win_T *wp, linenr_T lnum, char_u *line, colnr_T len);
 int linetabsize(win_T *wp, linenr_T lnum);
+int linetabsize_eol(win_T *wp, linenr_T lnum);
 int linetabsize_no_outer(win_T *wp, linenr_T lnum);
 void win_linetabsize_cts(chartabsize_T *cts, colnr_T len);
 int vim_isIDc(int c);