match: fix re2 compability broken in 2e2699af5649 When using re2, we call test_match() instead of match() on the compiled regex object. While match() returns a matcher object or None, test_match() returns True or False. So since 2e2699af5649 running test on a machine with a re2 install fails in many places. Instead we make the code a bit more general and everything goes back to normal.

py3: add b'' prefixes to new doctests in match.py # skip-blame as just b'' prefixes Differential Revision: https://phab.mercurial-scm.org/D6221