patch 8.2.5019: cannot get the first screen column of a character

Problem:    Cannot get the first screen column of a character.
Solution:   Let virtcol() optionally return a list. (closes #10482,
            closes #7964)
diff --git a/src/testdir/test_functions.vim b/src/testdir/test_functions.vim
index 1a05a59..af07a64 100644
--- a/src/testdir/test_functions.vim
+++ b/src/testdir/test_functions.vim
@@ -2947,4 +2947,15 @@
   endif
 endfunc
 
+" Test for virtcol()
+func Test_virtcol()
+  enew!
+  call setline(1, "the\tquick\tbrown\tfox")
+  norm! 4|
+  call assert_equal(8, virtcol('.'))
+  call assert_equal(8, virtcol('.', v:false))
+  call assert_equal([4, 8], virtcol('.', v:true))
+  bwipe!
+endfunc
+
 " vim: shiftwidth=2 sts=2 expandtab