patch 9.0.1008: test for swapfilelist() fails on MS-Windows

Problem:    Test for swapfilelist() fails on MS-Windows.
Solution:   Only check the tail of the path.  Mark a test as flaky.

src/testdir/test_vimscript.vim

@@ -5977,6 +5977,9 @@ endfunc
 
 " interrupt right before a catch is invoked in a script
 func Test_ignore_catch_after_intr_1()
+  " for unknown reasons this test sometimes fails on MS-Windows.
+  let g:test_is_flaky = 1
+
   XpathINIT
   let lines =<< trim [CODE]
     try