iOS port (for desktop_version)

[leo60228]

Changes:

An iOS port of the C++ version to go with the Android port in #1004. The same caveats as that PR apply. An Xcode project for the ARM64 simulator can be created with a command like the following:

cmake .. -GXcode -DCMAKE_SYSTEM_NAME=iOS -DSDL2_FRAMEWORK=$HOME/SDL2-2.28.5/Xcode/SDL/Products/SDL2.xcframework/ios-arm64_x86_64-simulator/SDL2.framework -DCMAKE_OSX_SYSROOT=iphonesimulator -DCMAKE_OSX_ARCHITECTURES=arm64 -DDATA_ZIP=$HOME/Downloads/data.zip

Similar commands should work for the x86_64 simulator and real hardware, though I haven't tested the former yet. Some further changes will likely be required to properly support app signing, though I think the details of that might differ between free and paid developer accounts? To force Xcode to build for real hardware without signing, you can use this command:

xcodebuild -verbose -project VVVVVV.xcodeproj -configuration Release -target VVVVVV archive CODE_SIGN_IDENTITY="" CODE_SIGNING_REQUIRED=NO CODE_SIGNING_ALLOWED=NO

A tvOS port would likely be fairly easy (and could potentially capitalize on a market for platformers playable with the Siri Remote?), but the only non-hacky way to store save data on tvOS is via Game Center, which requires a paid developer account.

Legal Stuff:

By submitting this pull request, I confirm that...

• [x] My changes may be used in a future commercial release of VVVVVV
• [x] I will be credited in a CONTRIBUTORS file and the "GitHub Friends" section of the credits for all of said releases, but will NOT be compensated for these changes unless there is a prior written agreement

[leo60228]

Here's an IPA for testing: https://drive.google.com/file/d/1Szx9lOgHgcL2rb-uQlZFOE7g9BBjJ_vA/view?usp=sharing

Apple doesn't want you to be able to install an IPA directly, but you can use a tool like AltServer or TrollStore to do so.