CI failure indicating it isn't redundant, but could still potentially be made faster since non-absolute paths should be relatively rare now:

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FAIL: test_s_option (test.test_site.HelperFunctionsTests)

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Traceback (most recent call last):

  File "/home/travis/build/python/cpython/Lib/test/test_site.py", line 173, in test_s_option

    self.assertIn(usersite, sys.path)

AssertionError: '/home/travis/.local/lib/python3.7/site-packages' not found in ['', '/usr/local/lib/python37.zip', '/home/travis/build/python/cpython/Lib', '/home/travis/build/python/cpython/build/lib.linux-x86_64-3.7-pydebug']

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FAIL: test_abs_paths (test.test_site.ImportSideEffectTests)

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Traceback (most recent call last):

  File "/home/travis/build/python/cpython/Lib/test/test_site.py", line 365, in test_abs_paths

    .format(os__file__.decode('ascii')))

AssertionError: False is not true : expected absolute path, got ../../Lib/os.py

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