revsetlang: do not pass in non-bytes to parse() Since parse() isn't a simple function, we shouldn't expect it would raise TypeError or ValueError for invalid inputs. Before, TypeError was raised at 'if pos != len(spec)', which was quite late to report an error. This patch also makes tokenize() detect invalid object before converting it to a py3-safe bytes. Spotted while adding the 'revset(...)' hack to _parsewith().