[TVOS] Adds tvOS compatibility.

[darionco]

This PR adds compatibility for tvOS by configuring the project files and adding a new script: maketvos.py which builds JavaScriptCore-tvOS.framework that can be used in tvOS projects.

[phoboslab]

Awesome!

Can you explain why this needs to be a different .framework though? Couldn't it be merged as just another slice in the same lib?

[darionco]

I have not tried that, I just followed Apple's examples in which they actually have different frameworks for iOS and tvOS. It made sense since tvOS is an ARM64 platform, the same as some iOS devices.

[phoboslab]

So, the question is, what actually makes the lib that is built for arm64 tvOS different from the one that's built for arm64 iOS? Why is it a different binary at all? Maybe it's just a flag somewhere in the lib that marks it as "tvOS compatible"?

I'll try to build the lib with your maketvos.py and then see if I can stick into the lib for iOS & Simulator.

[phoboslab]

> lipo -create JavaScriptCore-ios JavaScriptCore-tvos -output JavaScriptCore-universal.lib
fatal error: lipo JavaScriptCore-ios and JavaScriptCore-tvos have the same architectures (x86_64) and can't be in the same fat output file

Well, I guess we have to build two frameworks after all.

Thanks!