[AltJIT] Adds AltJIT CLI tool to enable JIT on devices running iOS 17+

Commands:

altjit enable [app/pid] --udid [udid]
* Enables JIT for given app/process

altjit mount --udid [udid]
* Mounts personalized developer disk

AltJIT/Extensions/Task+Timeout.swift

@@ -0,0 +1,57 @@
+//
+//  Task+Timeout.swift
+//  AltPackage
+//
+//  Created by Riley Testut on 8/31/23.
+//  Copyright © 2023 Riley Testut. All rights reserved.
+//
+//  Based heavily on https://forums.swift.org/t/running-an-async-task-with-a-timeout/49733/13
+//
+
+import Foundation
+
+struct TimedOutError: LocalizedError
+{
+    var duration: TimeInterval
+    
+    public var errorDescription: String? {
+        //TODO: Change pluralization for 1 second.
+        let errorDescription = String(format: NSLocalizedString("The task timed out after %@ seconds.", comment: ""), self.duration.formatted())
+        return errorDescription
+    }
+}
+
+///
+/// Execute an operation in the current task subject to a timeout.
+///
+/// - Parameters:
+///   - seconds: The duration in seconds `operation` is allowed to run before timing out.
+///   - operation: The async operation to perform.
+/// - Returns: Returns the result of `operation` if it completed in time.
+/// - Throws: Throws ``TimedOutError`` if the timeout expires before `operation` completes.
+///   If `operation` throws an error before the timeout expires, that error is propagated to the caller.
+func withTimeout<R>(seconds: TimeInterval, file: StaticString = #file, line: Int = #line, operation: @escaping @Sendable () async throws -> R) async throws -> R
+{
+    return try await withThrowingTaskGroup(of: R.self) { group in
+        let deadline = Date(timeIntervalSinceNow: seconds)
+
+        // Start actual work.
+        group.addTask {
+            return try await operation()
+        }
+        // Start timeout child task.
+        group.addTask {
+            let interval = deadline.timeIntervalSinceNow
+            if interval > 0 {
+                try await Task.sleep(for: .seconds(interval))
+            }
+            try Task.checkCancellation()
+            // We’ve reached the timeout.
+            throw TimedOutError(duration: seconds)
+        }
+        // First finished child task wins, cancel the other task.
+        let result = try await group.next()!
+        group.cancelAll()
+        return result
+    }
+}