Windows buildbots didn't like a6f0cc1820f4 :) Fix is incoming.

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FAIL: test_compile_dir_pathlike (test.test_compileall.CompileallTests)
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Traceback (most recent call last):
  File "D:\buildarea\3.6.ware-win81-release\build\lib\test\test_compileall.py", line 161, in test_compile_dir_pathlike
    self.assertIn("Listing '{}'...".format(self.directory), stdout.getvalue())
AssertionError: "Listing 'D:\\temp\\tmpuziqv_kw'..." not found in "Listing 'D:\\\\temp\\\\tmpuziqv_kw'...\nListing 'D:\\\\temp\\\\tmpuziqv_kw\\\\_subdir'...\nCompiling 'D:\\\\temp\\\\tmpuziqv_kw\\\\_subdir\\\\_test3.py'...\nCompiling 'D:\\\\temp\\\\tmpuziqv_kw\\\\_test.py'...\nCompiling 'D:\\\\temp\\\\tmpuziqv_kw\\\\_test2.py'...\n"

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FAIL: test_compile_file_pathlike (test.test_compileall.CompileallTests)
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Traceback (most recent call last):
  File "D:\buildarea\3.6.ware-win81-release\build\lib\test\test_compileall.py", line 111, in test_compile_file_pathlike
    "Compiling '{}'...\n".format(self.source_path))
AssertionError: "Compiling 'D:\\\\temp\\\\tmpqvjkm0fm\\\\_test.py'...\n" != "Compiling 'D:\\temp\\tmpqvjkm0fm\\_test.py'...\n"
- Compiling 'D:\\temp\\tmpqvjkm0fm\\_test.py'...
?              -     -            -
+ Compiling 'D:\temp\tmpqvjkm0fm\_test.py'...