Package dawn artifacts/required files into xcframework for easier integration

[SoylentGraham]

• Dont require user to place dawn artifacts (or anything!) into /usr/local/** #12

Improvement

These changes to the package setup mean the dylib, dawn headers, and dawn.json are all bundled into an .xcframework which SPM consumes quite nicely.

• Now we don't need any files added to the sytem in /usr/local etc
  • dylib & dawn headers in xcframework
  • pkgconfig replaced with publicHeadersPath and webgpu.h to generate the webgpu symbols (eg WGPUBool)
• This can later move so the xcframework can come from an URL (ie. github workflow -> release, and automate creation from dawn's own code)
• This now automatically includes the dylib into any product of a project that requires it (currently the setup fails as the dylib isn't bundled with any projects)
• WebGPU C->Swift symbols now come via publicHeadersPath in CWebGPU and require webgpu.h (and ONLY this header)

User Instructions

• Build dawn as before, but copy
  • libwebgpu_dawn.dylib
  • dawn's include/
  • dawn's dawn.json
• Into Sources/DawnNative/ and then run cd Soruces/DawnNaive && ./CreateXCFramework.sh
• This will generate a Sources/DawnNative/webgpu_dawn.xcframework
• The Swift package then gets all it's dependencies from the xcframework when building

Todo

• Make a seperate repos for xcframework generation
• Update readme

[SoylentGraham]

Currently xcode fails to Archive (for app store) any projects - not sure if this is related to my changes or not

dyld[38443]: Library not loaded: @rpath/ArgumentParser_39B7DAEE4DD359BE_PackageProduct.framework/Versions/A/ArgumentParser_39B7DAEE4DD359BE_PackageProduct
  Referenced from: <BA83F552-06A5-33D1-B7AB-3C2508F3A7D9> /Volumes/Sandisk/Xcode_DerivedData/HenryBettsWebGpuDemo-doptxfxqkfjmwzefxxqpaktwloon/Build/Intermediates.noindex/ArchiveIntermediates/HenryBettsWebGpuDemo/IntermediateBuildFilesPath/UninstalledProducts/macosx/generate-webgpu
  Reason: tried: '/usr/lib/swift/ArgumentParser_39B7DAEE4DD359BE_PackageProduct.framework/Versions/A/ArgumentParser_39B7DAEE4DD359BE_PackageProduct' (no such file, not in dyld cache), '/System/Volumes/Preboot/Cryptexes/OS/usr/lib/swift/ArgumentParser_39B7DAEE4DD359BE_PackageProduct.framework/Versions/A/ArgumentParser_39B7DAEE4DD359BE_PackageProduct' (no such file), '/usr/lib/swift/ArgumentParser_39B7DAEE4DD359BE_PackageProduct.framework/Versions/A/ArgumentParser_39B7DAEE4DD359BE_PackageProduct' (no such file, not in dyld cache), '/System/Volumes/Preboot/Cryptexes/OS/usr/lib/swift/ArgumentParser_39B7DAEE4DD359BE_PackageProduct.framework/Versions/A/ArgumentParser_39B7DAEE4DD359BE_PackageProduct' (no such file)
/Volumes/Sandisk/Xcode_DerivedData/HenryBettsWebGpuDemo-doptxfxqkfjmwzefxxqpaktwloon/Build/Intermediates.noindex/ArchiveIntermediates/HenryBettsWebGpuDemo/IntermediateBuildFilesPath/swift-webgpu.build/Release/WebGPU.build/Script-16908758398532019134.sh: line 20: 38443 Abort trap: 6           /usr/bin/sandbox-exec -p "(version 1)

edit: same error when building release

[SoylentGraham]

To get the right artifacts, after building via ninja (as per current instructions), I cannot find the correct artifacts...
only when doing sudo ninja install can I find the .dylib and the correct includes.

todo:

• Find where this dylib is (does install do a final link??) and dont require /usr/lib install
• find out which are the correct includes to be used with this script

[SoylentGraham]

Current setup is building a hardcoded path to /Volumes/Code/dawn/out/Release/src/dawn/platform/libdawn_platform.dylib in libwebgpu_dawn.framework/webgpu_dawn so clearing out dawn artifacts (or using on another system) fails

Need to fix this