Add arm64-ios & arm64-tvos runtime packs for simulator and produce new runtime packs

[marek-safar]

We need a different build for ios simulator running on M1 machines. It has the same arch as 64 bits iOS bit the native assets cannot be shared. This is something that Apple might change in the future though.

I'd suggest deriving it from the existing ios-arm64 RID.

/cc @rolfbjarne

I couldn't figure out the best area label to add to this issue. If you have write-permissions please help me learn by adding exactly one area label.

[directhex]

To confirm my understanding of the issue:

• Currently, ios-x64 means "Simulator" and ios-arm64 means "Device"
• But on M1, the Simulator is arm64
• The Simulator and Device runtimes differ in ways other than the CPU architecture, so we need both ios-arm64-device and ios-arm64-simulator configurations

Should we also rename ios-x64 to unify with whatever ios-arm64-simulator ends up looking like? I know there's not a huge likelihood of ios-x64-device being a thing that exists

[steveisok]

Your understanding is my understanding.

I think having ios-arch-simulator packs makes a lot of sense. So, yes, I would support an x64 rename.

[marek-safar]

I agree we should not suffix with -device and that it should be the shorter rid. I'm thinking about

ios-x64-sim
ios-arm64-sim

This also means we need to change existing RIDs

[directhex]

Looking at it, the precedent we have for sub-variants is Alpine Linux, i.e. linux-x64 -> linux-musl-x64. As far as the build system goes, it's easier to declare "ios-sim is a variant of ios" than "x64-sim is a variant of x64"

[steveisok]

If I understand the RID structure correctly, I think that shouldn't hurt us either way.

[directhex]

Does this discussion also apply to tvOS?