patch 9.0.0363: common names in test files causes tests to be flaky

Problem:    Common names in test files causes tests to be flaky.
Solution:   Use more specific names.
diff --git a/src/testdir/test_window_cmd.vim b/src/testdir/test_window_cmd.vim
index bea612f..44fd646 100644
--- a/src/testdir/test_window_cmd.vim
+++ b/src/testdir/test_window_cmd.vim
@@ -1083,12 +1083,12 @@
     endtry
   endwhile
 
-  call writefile(['first', 'second', 'third'], 'Xfile1')
-  call writefile([], 'Xfile2')
-  call writefile([], 'Xfile3')
+  call writefile(['first', 'second', 'third'], 'Xnorfile1')
+  call writefile([], 'Xnorfile2')
+  call writefile([], 'Xnorfile3')
 
   " Argument list related commands
-  args Xfile1 Xfile2 Xfile3
+  args Xnorfile1 Xnorfile2 Xnorfile3
   next
   for cmd in ['sargument 2', 'snext', 'sprevious', 'sNext', 'srewind',
 			\ 'sfirst', 'slast']
@@ -1099,13 +1099,13 @@
   " Buffer related commands
   set modified
   hide enew
-  for cmd in ['sbuffer Xfile1', 'sbnext', 'sbprevious', 'sbNext', 'sbrewind',
+  for cmd in ['sbuffer Xnorfile1', 'sbnext', 'sbprevious', 'sbNext', 'sbrewind',
 		\ 'sbfirst', 'sblast', 'sball', 'sbmodified', 'sunhide']
     call assert_fails(dir .. cmd, 'E36:')
   endfor
 
   " Window related commands
-  for cmd in ['split', 'split Xfile2', 'new', 'new Xfile3', 'sview Xfile1',
+  for cmd in ['split', 'split Xnorfile2', 'new', 'new Xnorfile3', 'sview Xnorfile1',
 		\ 'sfind runtest.vim']
     call assert_fails(dir .. cmd, 'E36:')
   endfor
@@ -1128,7 +1128,7 @@
     call assert_fails(dir .. 'lopen', 'E36:')
 
     " Preview window
-    call assert_fails(dir .. 'pedit Xfile2', 'E36:')
+    call assert_fails(dir .. 'pedit Xnorfile2', 'E36:')
     call setline(1, 'abc')
     call assert_fails(dir .. 'psearch abc', 'E36:')
   endif
@@ -1136,15 +1136,15 @@
   " Window commands (CTRL-W ^ and CTRL-W f)
   if a:dir_arg == 'h'
     call assert_fails('call feedkeys("\<C-W>^", "xt")', 'E36:')
-    call setline(1, 'Xfile1')
+    call setline(1, 'Xnorfile1')
     call assert_fails('call feedkeys("gg\<C-W>f", "xt")', 'E36:')
   endif
   enew!
 
   " Tag commands (:stag, :stselect and :stjump)
   call writefile(["!_TAG_FILE_ENCODING\tutf-8\t//",
-        \ "second\tXfile1\t2",
-        \ "third\tXfile1\t3",],
+        \ "second\tXnorfile1\t2",
+        \ "third\tXnorfile1\t3",],
         \ 'Xtags')
   set tags=Xtags
   call assert_fails(dir .. 'stag second', 'E36:')
@@ -1166,9 +1166,9 @@
   endif
 
   %bwipe!
-  call delete('Xfile1')
-  call delete('Xfile2')
-  call delete('Xfile3')
+  call delete('Xnorfile1')
+  call delete('Xnorfile2')
+  call delete('Xnorfile3')
   only
 endfunc
 
@@ -1387,16 +1387,16 @@
 " window to another.
 func Test_close_dest_window()
   split
-  edit Xfile
+  edit Xdstfile
 
   " Test for BufLeave
   augroup T1
     au!
-    au BufLeave Xfile $wincmd c
+    au BufLeave Xdstfile $wincmd c
   augroup END
   wincmd b
   call assert_equal(1, winnr('$'))
-  call assert_equal('Xfile', @%)
+  call assert_equal('Xdstfile', @%)
   augroup T1
     au!
   augroup END
@@ -1410,7 +1410,7 @@
   augroup END
   wincmd t
   call assert_equal(1, winnr('$'))
-  call assert_equal('Xfile', @%)
+  call assert_equal('Xdstfile', @%)
   augroup T1
     au!
   augroup END
@@ -1595,12 +1595,12 @@
   call assert_fails('split', 'E342:')
   call assert_equal(1, winnr('$'))
 
-  edit Xfile1
-  edit Xfile2
+  edit Xwaffile1
+  edit Xwaffile2
   call test_alloc_fail(GetAllocId('newwin_wvars'), 0, 0)
-  call assert_fails('sb Xfile1', 'E342:')
+  call assert_fails('sb Xwaffile1', 'E342:')
   call assert_equal(1, winnr('$'))
-  call assert_equal('Xfile2', @%)
+  call assert_equal('Xwaffile2', @%)
   %bw!
 
   " FIXME: The following test crashes Vim