Support `flutter run` and `flutter drive` for `Mac Designed for iPad` apps on arm64 Macs

[jmagman]

Once Mac Designed for iPad are discoverable #141290 implement flutter run and flutter drive on these devices.

We originally didn't allow flutter run to avoid confusion with macOS-proper development when that platform was not yet in stable (see comment in #84411). Now that macOS development has been in stable for awhile, and arm64 Macs are far more prevalent, let's enable this to make it easier for developers to debug their app in whatever way Apple supports.

Test as many as the run and drive flags as possible. If any of them don't make sense for Mac Designed for iPad throw a toolExit() in the respective validateCommand() methods so it just fails instead of doing some weird behavior.

flutter/packages/flutter_tools/lib/src/commands/run.dart

Line 583 in d1f3ae7

Future<void> validateCommand() async {

flutter/packages/flutter_tools/lib/src/commands/drive.dart

Line 220 in d1f3ae7

Future<void> validateCommand() async {

Once implemented, validate it works from the IDE GUI.

Part of #125741

[jmagman]

1. Support building the app:
   

   flutter/packages/flutter_tools/lib/src/macos/macos_ipad_device.dart

   Lines 84 to 91 in eff2e7d

   	Future<void> buildForDevice({
   	String? mainPath,
   	required BuildInfo buildInfo,
   	}) async {
   	// Only attaching to a running app launched from Xcode is supported.
   	throw UnimplementedError('Building for "$name" is not supported.');
   	}
   	}

This will probably look almost identical to building an iOS app and can share the same logic.

flutter/packages/flutter_tools/lib/src/macos/macos_ipad_device.dart

Lines 63 to 75 in eff2e7d

	Future<LaunchResult> startApp(
	ApplicationPackage? package, {
	String? mainPath,
	String? route,
	required DebuggingOptions debuggingOptions,
	Map<String, Object?> platformArgs = const <String, Object>{},
	bool prebuiltApplication = false,
	bool ipv6 = false,
	String? userIdentifier,
	}) async {
	// Only attaching to a running app launched from Xcode is supported.
	throw UnimplementedError('Building for "$name" is not supported.');
	}

I suspect we can use the DesktopDevice super class implementation of these just by telling flutter where the executable is since it will run like a desktop app:

flutter/packages/flutter_tools/lib/src/macos/macos_ipad_device.dart

Line 60 in eff2e7d

String? executablePathForDevice(ApplicationPackage package, BuildInfo buildInfo) => null;

From Xcode it's building the into path/to/deriveddata/Build/Products/Debug-iphoneos/.XCInstall/Test Create.app

$ ll -R /Users/m/Library/Developer/Xcode/DerivedData/Runner-gnengnkipgqsumexkvwkdczgvrst/Build/Products/Debug-iphoneos/.XCInstall/Test\ Create.app
total 0
drwxr-xr-x@ 4 m  primarygroup  128 Jan  9 15:57 .
drwxr-xr-x  9 m  primarygroup  288 Jan 10 09:49 ..
lrw-r--r--  1 m  primarygroup   18 Jan  9 15:57 WrappedBundle -> Wrapper/Runner.app
drwxr-xr-x  4 m  primarygroup  128 Jan  9 15:57 Wrapper

/Users/m/Library/Developer/Xcode/DerivedData/Runner-gnengnkipgqsumexkvwkdczgvrst/Build/Products/Debug-iphoneos/.XCInstall/Test Create.app/Wrapper:
total 8
drwxr-xr-x   4 m  primarygroup  128 Jan  9 15:57 .
drwxr-xr-x@  4 m  primarygroup  128 Jan  9 15:57 ..
-rw-r--r--   1 m  primarygroup  618 Jan  9 15:57 BundleMetadata.plist
drwxr-xr-x  13 m  primarygroup  416 Jan  9 15:57 Runner.app

Where Runner.app looks a lot (identical to?) an iOS app. Hopefully there's some xcodebuild -destination we can use to have Xcode build that bundle for us.

[flutter-triage-bot]

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