Reland "[test] Fix cctest path separators on Windows"

test/intl/testcfg.py

Index: test/intl/testcfg.py
diff --git a/test/intl/testcfg.py b/test/intl/testcfg.py
index 9fc087e5f523fc46eda2b3c94f9951c638447d10..51fa1e1a88d2fe2b350be8b7b16f1db62b9bed88 100644
--- a/test/intl/testcfg.py
+++ b/test/intl/testcfg.py
@@ -46,7 +46,9 @@ class IntlTestSuite(testsuite.TestSuite):
       for filename in files:
         if (filename.endswith(".js") and filename != "assert.js" and
             filename != "utils.js"):
-          testname = os.path.join(dirname[len(self.root) + 1:], filename[:-3])
+          fullpath = os.path.join(dirname, filename)
+          relpath = fullpath[len(self.root) + 1 : -3]
+          testname = relpath.replace(os.path.sep, "/")
           test = testcase.TestCase(self, testname)
           tests.append(test)
     return tests