run-tests: allow hg executable to be hg.exe When running tests on Windows (via msys), user sometimes does not want to run them against source hg, but against compiled hg.exe. For that purpose, --with-hg option can be used, but currently run-tests.py prints a warning if the value of this argument is not a file with basename 'hg'. This patch allows such file to be 'hg.exe'.