Convert FileLengthRule to use SwiftSyntax instead of SourceKit for
improved performance and fewer false positives.
The SwiftSyntax implementation:
- Uses ViolationsSyntaxVisitor pattern with token traversal
- Correctly handles multiline tokens by counting all spanned lines
- Properly excludes comment-only and whitespace-only lines
- Accurately attributes trivia to correct line positions
- Extracts common line range logic to reduce code duplication
Danny Mösch
JP Simard
Martin Redington