patch 8.0.1302: still too many old style tests

Problem:    Still too many old style tests.
Solution:   Convert a few more tests to new style. (Yegappan Lakshmanan,
            closes #2326)
diff --git a/src/testdir/runtest.vim b/src/testdir/runtest.vim
index 08c0e68..8eef166 100644
--- a/src/testdir/runtest.vim
+++ b/src/testdir/runtest.vim
@@ -103,6 +103,10 @@
   " buffers.
   %bwipe!
 
+  " The test may change the current directory. Save and restore the
+  " directory after executing the test.
+  let save_cwd = getcwd()
+
   if exists("*SetUp")
     try
       call SetUp()
@@ -157,6 +161,8 @@
       break
     endif
   endwhile
+
+  exe 'cd ' . save_cwd
 endfunc
 
 func AfterTheTest()