rust-status: error on non-existent files in file_set file_set here consists of the files that were explicitly specified on the command line. Erroring on them matches the behavior of Python status.

rust-status: explicitly track bad file types Before this, we silently skipped bad file types. Now, we check to see if a path is an exact_match in our matcher, and if so, print an error for it, and only then do we skip it. A path will be an exact match when it's specified as an explicit command line argument, and this error-printing behavior is necessary for compatibility with Python status.

rust: de-hardcode glob_suffix We're adding patternmatcher in a subsequent commit, and this needs needs to be different for includematcher and patternmatcher.

rust: improve the type on DirsMultiset::from_manifest It could only return an HgPathError, but we didn't express this in the type, so we needed some unreachable!()s. Now that is expressed in the type.

rust: don't escape spaces in regex Spaces are not in fact a regex special character, and escaping them is not correct.

rust-filepatterns: also normalize RelPath These patterns should be normalized too; this at least does no harm, and is necessary for proper status support.

rust: simplify pattern file parsing Previously we kept the pattern syntax as a &[u8] until the last possible moment, which meant we had to handle potential errors when parsing that &[u8]. But such errors could never actually occur, given the structure of the code. Now we parse it eagerly (in two places) and pass it around as a PatternSyntax, so we can delete some error handling code. parse_one_pattern is in particular useful for parsing patterns passed on the command line, as we'll support later in this series.