patch 9.0.0323: using common name in tests leads to flaky tests

Problem:    Using common name in tests leads to flaky tests.
Solution:   Rename files and directories to be more specific.
diff --git a/src/testdir/test_autocmd.vim b/src/testdir/test_autocmd.vim
index a996c8b..e4b76db 100644
--- a/src/testdir/test_autocmd.vim
+++ b/src/testdir/test_autocmd.vim
@@ -717,14 +717,14 @@
   call assert_equal('++', g:val)
 
   " Also get BufEnter when editing a directory
-  call mkdir('Xdir')
-  split Xdir
+  call mkdir('Xbufenterdir')
+  split Xbufenterdir
   call assert_equal('+++', g:val)
 
   " On MS-Windows we can't edit the directory, make sure we wipe the right
   " buffer.
-  bwipe! Xdir
-  call delete('Xdir', 'd')
+  bwipe! Xbufenterdir
+  call delete('Xbufenterdir', 'd')
   au! BufEnter
 
   " Editing a "nofile" buffer doesn't read the file but does trigger BufEnter
@@ -2723,16 +2723,16 @@
 endfunc
 
 func Test_autocmd_in_try_block()
-  call mkdir('Xdir')
+  call mkdir('Xintrydir')
   au BufEnter * let g:fname = expand('%')
   try
-    edit Xdir/
+    edit Xintrydir/
   endtry
-  call assert_match('Xdir', g:fname)
+  call assert_match('Xintrydir', g:fname)
 
   unlet g:fname
   au! BufEnter
-  call delete('Xdir', 'rf')
+  call delete('Xintrydir', 'rf')
 endfunc
 
 func Test_autocmd_SafeState()