       Option.disableDeserializationRecovery,
       Option.disableDiagnosticPasses,
       Option.disableExperimentalClangImporterDiagnostics,
+      Option.disableExperimentalOpenedExistentialTypes,
       Option.disableFailOnError,
       Option.disableFailOnError_,
       Option.disableGenericMetadataPrespecialization,

  public static let candidateModuleFile: Option = Option("-candidate-module-file", .separate, attributes: [.helpHidden, .frontend, .noDriver], metaVar: "<path>", helpText: "Specify Swift module may be ready to use for an interface")
  public static let checkApiAvailabilityOnly: Option = Option("-check-api-availability-only", .flag, attributes: [.helpHidden, .frontend, .noInteractive], helpText: "Only check the availability of the APIs, ignore function bodies")
  public static let checkOnoneCompleteness: Option = Option("-check-onone-completeness", .flag, attributes: [.helpHidden, .frontend, .noDriver], helpText: "Print errors if the compile OnoneSupport module is missing symbols")
  public static let clangTarget: Option = Option("-clang-target", .separate, attributes: [.frontend], helpText: "Separately set the target we should use for internal Clang instance")
  public static let codeCompleteCallPatternHeuristics: Option = Option("-code-complete-call-pattern-heuristics", .flag, attributes: [.helpHidden, .frontend, .noDriver], helpText: "Use heuristics to guess whether we want call pattern completions")
  public static let codeCompleteInitsInPostfixExpr: Option = Option("-code-complete-inits-in-postfix-expr", .flag, attributes: [.helpHidden, .frontend, .noDriver], helpText: "Include initializers when completing a postfix expression")

      Option.disableTypoCorrection,
      Option.disableVerifyExclusivity,
      Option.disallowForwardingDriver,
      Option.downgradeTypecheckInterfaceError,
      Option.driverAlwaysRebuildDependents,
      Option.driverBatchCount,
