The "path" recorded for timing purposes is only used as a key into a dictionary. It is never used as an actual path to a filesystem API, therefore we should use '/' as the canonical separator so that Unix and Windows machines can share timing data. This also ensures that the lit testing works across platforms.
Could we use getFullName() here? Or if the config-qualified name is undesirable, we could extract this into Test::getName().
def getFullName(self): return self.suite.config.name + ' :: ' + '/'.join(self.path_in_suite)