[AltServer] Supports enabling JIT on devices running iOS 17

AltServer embeds the AltJIT CLI tool in its app bundle and runs it as an admin subprocess.

AltServer/Extensions/Logger+AltServer.swift

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+//
+//  Logger+AltServer.swift
+//  AltStore
+//
+//  Created by Riley Testut on 9/6/23.
+//  Copyright © 2023 Riley Testut. All rights reserved.
+//
+
+import OSLog
+
+extension Logger
+{
+    static let altserverSubsystem = Bundle.main.bundleIdentifier!
+    
+    static let main = Logger(subsystem: altserverSubsystem, category: "AltServer")
+}

AltServer/Extensions/Process+STPrivilegedTask.swift

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+//
+//  Process+STPrivilegedTask.swift
+//  AltServer
+//
+//  Created by Riley Testut on 8/22/23.
+//  Copyright © 2023 Riley Testut. All rights reserved.
+//
+
+import Foundation
+import Security
+import OSLog
+
+import STPrivilegedTask
+
+extension Process
+{
+    class func runAsAdmin(_ program: String, arguments: [String], authorization: AuthorizationRef? = nil) throws -> AuthorizationRef?
+    {
+        var launchPath = "/usr/bin/" + program
+        if !FileManager.default.fileExists(atPath: launchPath)
+        {
+            launchPath = "/bin/" + program
+        }
+        
+        if !FileManager.default.fileExists(atPath: launchPath)
+        {
+            launchPath = program
+        }
+        
+        Logger.main.info("Launching admin process: \(launchPath, privacy: .public)")
+        
+        let task = STPrivilegedTask()
+        task.launchPath = launchPath
+        task.arguments = arguments
+        task.freeAuthorizationWhenDone = false
+        
+        let errorCode: OSStatus
+        
+        if let authorization = authorization
+        {
+            errorCode = task.launch(withAuthorization: authorization)
+        }
+        else
+        {
+            errorCode = task.launch()
+        }
+        
+        let executableURL = URL(fileURLWithPath: launchPath)
+        guard errorCode == 0 else { throw ProcessError.failed(executableURL: executableURL, exitCode: errorCode, output: nil) }
+        
+        task.waitUntilExit()
+        
+        Logger.main.info("Admin process \(launchPath, privacy: .public) terminated with exit code \(task.terminationStatus, privacy: .public).")
+        
+        guard task.terminationStatus == 0 else {
+            let executableURL = URL(fileURLWithPath: launchPath)
+            
+            let outputData = task.outputFileHandle.readDataToEndOfFile()
+            if let outputString = String(data: outputData, encoding: .utf8), !outputString.isEmpty
+            {
+                throw ProcessError.failed(executableURL: executableURL, exitCode: task.terminationStatus, output: outputString)
+            }
+            else
+            {
+                throw ProcessError.failed(executableURL: executableURL, exitCode: task.terminationStatus, output: nil)
+            }
+        }
+        
+        return task.authorization
+    }
+}