impellerc and libtessellator should run natively on Apple Silicon arm machines #109892
Description
The bin/cache/artifacts/engine/darwin-x64/impellerc artifact only contains a x64 slice, so runs with Rosetta on an arm64 Mac. Ship a native arm64 variant to run on Apple Silicon host machines.
Saw this on a bad luci run that was missing Rosetta:
stderr: [ +2 ms] ProcessException: Bad CPU type in executable
stderr: Command: /opt/s/w/ir/x/w/recipe_cleanup/tmpxs3pju7o/flutter sdk/bin/cache/artifacts/engine/darwin-x64/impellerc --sksl --iplr --sl=/opt/s/w/ir/x/t/flutter_module_test.T4OVDk/hello_module/flutter-frameworks/Debug/iphoneos/App.framework/flutter_assets/shaders/ink_sparkle.frag --spirv=/opt/s/w/ir/x/t/flutter_module_test.T4OVDk/hello_module/flutter-frameworks/Debug/iphoneos/App.framework/flutter_assets/shaders/ink_sparkle.frag.spirv --input=/opt/s/w/ir/x/w/recipe_cleanup/tmpxs3pju7o/flutter sdk/packages/flutter/lib/src/material/shaders/ink_sparkle.frag --input-type=frag --include=/opt/s/w/ir/x/w/recipe_cleanup/tmpxs3pju7o/flutter sdk/packages/flutter/lib/src/material/shaders