Revert of [test] Fix cctest path separators on Windows

test/mozilla/testcfg.py

Index: test/mozilla/testcfg.py
diff --git a/test/mozilla/testcfg.py b/test/mozilla/testcfg.py
index 70665cb807d0723046ba2ad7ced9be6406b45b82..70a7ac663cde287e87f73808dd1fed2d96f41139 100644
--- a/test/mozilla/testcfg.py
+++ b/test/mozilla/testcfg.py
@@ -81,9 +81,8 @@
         files.sort()
         for filename in files:
           if filename.endswith(".js") and not filename in FRAMEWORK:
-            fullpath = os.path.join(dirname, filename)
-            relpath = fullpath[len(self.testroot) + 1 : -3]
-            testname = relpath.replace(os.path.sep, "/")
+            testname = os.path.join(dirname[len(self.testroot) + 1:],
+                                    filename[:-3])
             case = testcase.TestCase(self, testname)
             tests.append(case)
     return tests