Fix whisper.objc Xcode project

[iamcgn]

This PR updates the whisper.objc Xcode project so that it compiles. The project referenced 2 files that had been renamed and was missing references to ggml-cpu-traits.c and ggml-cpu-traits.h. I also had to explicitly add the -x c++ flag to convince Xcode to compile ggml-cpu-aarch64.cpp as C++ rather than C. I tested these changes in Xcode 16.2.

[ggerganov]

Thanks! Let's re-enable the whisper.objc build in the CI to make sure it works now. Just uncomment these:

whisper.cpp/.github/workflows/build.yml

Lines 679 to 682 in b82d305

	#- name: Build objc example
	# run: xcodebuild -project examples/whisper.objc/whisper.objc.xcodeproj -scheme whisper.objc -configuration ${{ matrix.build }} -sdk iphoneos build

[toxtesters]

Beautiful, thank you for fixing this so quickly!

Just FYI the SwiftUI example was also broken when I tried it, not sure if it's for the same reason though. I didn't investigate very deeply.

[ggerganov]

The CI encounters a code signing error:

https://github.com/ggerganov/whisper.cpp/actions/runs/12779469282/job/35634823346?pr=2736#step:6:175

I think we need to add CODE_SIGNING_REQUIRED=NO CODE_SIGN_IDENTITY= to the build.

[iamcgn]

Alright, I disabled code signing and got the build working locally. Hopefully it works in CI!

@ggerganov I also fixed the SwiftUI example. Would you prefer I open a separate PR for that or just add it here? It's just updating Package.swift to reflect the recent changes.

[ggerganov]

Great! Let's make the SwiftUI changes in another PR. I will merge this one as soon as the CI is green.

[ggerganov]

After the recent ggml sync (#2737), there are now a couple of new files (gguf.h/gguf.cpp) that have to be added to the projects:

https://github.com/ggerganov/whisper.cpp/actions/runs/12801432106/job/35705816929?pr=2736#step:6:320

[ggerganov]

@iamcgn Thanks for the help!