Avoid .unique

Source/SwiftLintCore/Extensions/Configuration+LintableFiles.swift

@@ -60,11 +60,17 @@ extension Configuration {
  ///
  /// - returns: The input paths after removing the excluded paths.
  public func filterExcludedPaths(in paths: [String]...) -> [String] {
+ let allPaths = paths.flatMap { $0 }
+ #if os(Linux)
+ let result = NSMutableOrderedSet(capacity: allPaths.count)
+ result.addObjects(from: allPaths)
+ #else
+ let result = NSMutableOrderedSet(array: allPaths)
+ #endif
  let exclusionPatterns = self.excludedPaths.map { Glob.createFilenameMatcher(root: rootDirectory, pattern: $0) }
- let pathsWithoutExclusions = paths
- .flatMap { $0 }
+ return result
+ .map { $0 as! String } // swiftlint:disable:this force_cast
  .filter { !exclusionPatterns.anyMatch(filename: $0) }
- return pathsWithoutExclusions.unique
  }
 
  /// Returns the file paths that are excluded by this configuration using filtering by absolute path prefix.