patch 9.0.0463: command line test leaves directory behind

Problem:    Command line test leaves directory behind.
Solution:   Use the "R" flag on the first mkdir(). (Dominique Pellé,
            closes #11127)
diff --git a/src/testdir/test_cmdline.vim b/src/testdir/test_cmdline.vim
index 73bdbb4..7febc12 100644
--- a/src/testdir/test_cmdline.vim
+++ b/src/testdir/test_cmdline.vim
@@ -2149,7 +2149,7 @@
   call VerifyScreenDump(buf, 'Test_wildmenu_pum_13', {})
 
   " Directory name completion
-  call mkdir('Xnamedir/XdirA/XdirB', 'p')
+  call mkdir('Xnamedir/XdirA/XdirB', 'pR')
   call writefile([], 'Xnamedir/XfileA')
   call writefile([], 'Xnamedir/XdirA/XfileB')
   call writefile([], 'Xnamedir/XdirA/XdirB/XfileC')
@@ -2229,7 +2229,7 @@
   call VerifyScreenDump(buf, 'Test_wildmenu_pum_31', {})
 
   " Tests a directory name contained full-width characters.
-  call mkdir('Xnamedir/あいう', 'pR')
+  call mkdir('Xnamedir/あいう', 'p')
   call writefile([], 'Xnamedir/あいう/abc')
   call writefile([], 'Xnamedir/あいう/xyz')
   call writefile([], 'Xnamedir/あいう/123')