patch 8.2.3627: difficult to know where the text starts in a window

Problem:    difficult to know where the text starts in a window. (Sergey
            Vlasov)
Solution:   Add the "textoff" entry in the result of getwininfo().
            (closes #9163)
diff --git a/src/evalwindow.c b/src/evalwindow.c
index c905715..c8c1442 100644
--- a/src/evalwindow.c
+++ b/src/evalwindow.c
@@ -407,6 +407,7 @@
 #endif
     dict_add_number(dict, "width", wp->w_width);
     dict_add_number(dict, "wincol", wp->w_wincol + 1);
+    dict_add_number(dict, "textoff", win_col_off(wp));
     dict_add_number(dict, "bufnr", wp->w_buffer->b_fnum);
 
 #ifdef FEAT_TERMINAL
diff --git a/src/testdir/test_bufwintabinfo.vim b/src/testdir/test_bufwintabinfo.vim
index f201753..1d8e74a 100644
--- a/src/testdir/test_bufwintabinfo.vim
+++ b/src/testdir/test_bufwintabinfo.vim
@@ -50,6 +50,7 @@
 
   only
   let w1_id = win_getid()
+  setl foldcolumn=3
   new
   let w2_id = win_getid()
   tabnew | let w3_id = win_getid()
@@ -68,6 +69,7 @@
   call assert_equal(winbufnr(2), winlist[1].bufnr)
   call assert_equal(winheight(2), winlist[1].height)
   call assert_equal(1, winlist[1].wincol)
+  call assert_equal(3, winlist[1].textoff)  " foldcolumn
   call assert_equal(tablineheight + winheight(1) + 2, winlist[1].winrow)
 
   call assert_equal(1, winlist[2].winnr)
diff --git a/src/version.c b/src/version.c
index c54307e..7bb852f 100644
--- a/src/version.c
+++ b/src/version.c
@@ -758,6 +758,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    3627,
+/**/
     3626,
 /**/
     3625,