vim-patch:8.1.0212: preferred cursor column not set in interfaces

Problem:    Preferred cursor column not set in interfaces.
Solution:   Set w_set_curswant when setting the cursor. (David Hotham,
            closes vim/vim#3060)
53901442f3

This contains test_ruby changes only.
test_python changes were ported before.

src/nvim/testdir/test_ruby.vim

@@ -59,3 +59,16 @@ func Test_rubyfile()
   call assert_fails('rubyfile ' . tempfile)
   call delete(tempfile)
 endfunc
+
+func Test_set_cursor()
+  " Check that setting the cursor position works.
+  new
+  call setline(1, ['first line', 'second line'])
+  normal gg
+  rubydo $curwin.cursor = [1, 5]
+  call assert_equal([1, 6], [line('.'), col('.')])
+
+  " Check that movement after setting cursor position keeps current column.
+  normal j
+  call assert_equal([2, 6], [line('.'), col('.')])
+endfunc