tests: write directly to stdout to avoid b'' prefixes This enables the test to pass on Python 3. Differential Revision: https://phab.mercurial-scm.org/D5668

tests: handle string escaping/encoding on Python 3 This code was failing on Python 3 for a few reasons: 1) sys.argv is str and str doesn't have a .decode() 2) the "string_escape" encoding was renamed to "unicode_escape" It is wonky casting to bytes to str to bytes. But this is test code, so meh. I don't believe we exercise any code paths in these tests where the arguments aren't ascii. Differential Revision: https://phab.mercurial-scm.org/D5667