patch 9.0.0964: status line not redrawn when 'splitkeep' is "screen"

Problem:    Status line of other window not redrawn when dragging it when
            'splitkeep' is set to "screen".
Solution:   Set w_redr_status earlier. (Luuk van Baal, closes #11635,
            closes #11632)

src/testdir/dumps/Test_splitkeep_status_1.dump

@@ -0,0 +1,10 @@
+|a+0&#ffffff0| @73
+|b| @73
+|c| @73
+|~+0#4040ff13&| @73
+|~| @73
+|[+1#0000000&|N|o| |N|a|m|e|]| @47|1|,|1| @11|A|l@1
+>b+0&&| @73
+|c| @73
+|[+3&&|N|o| |N|a|m|e|]| @47|2|,|1| @11|B|o|t
+|:+0&&|c|a|l@1| |w|i|n|_|m|o|v|e|_|s|t|a|t|u|s|l|i|n|e|(|w|i|n|,| |1|)| @41

src/testdir/test_window_cmd.vim

@@ -1895,4 +1895,22 @@ function Test_splitkeep_fold()
   call VerifyScreenDump(buf, 'Test_splitkeep_fold_4', {})
 endfunction
 
+function Test_splitkeep_status()
+  CheckScreendump
+
+  let lines =<< trim END
+    call setline(1, ['a', 'b', 'c'])
+    set nomodified
+    set splitkeep=screen
+    let win = winnr()
+    wincmd s
+    wincmd j
+  END
+  call writefile(lines, 'XTestSplitkeepStatus', 'D')
+  let buf = RunVimInTerminal('-S XTestSplitkeepStatus', #{rows: 10})
+
+  call term_sendkeys(buf, ":call win_move_statusline(win, 1)\<CR>")
+  call VerifyScreenDump(buf, 'Test_splitkeep_status_1', {})
+endfunction
+
 " vim: shiftwidth=2 sts=2 expandtab