Mac and "PANIC: Missing emulator engine program for 'arm' CPU."
Just tried and verified on my Mac, to solve this problem, you need to specify the -kernel path manually. i.e.
$ ~/Library/Android/sdk/emulator/emulator @Galaxy_Nexus_Jelly_Bean_API_16 -kernel ~/Library/Android/sdk/system-images/android-16/default/armeabi-v7a/kernel-qemu
Some references for you:
Emulator error: This AVD's configuration is missing a kernel file
https://developer.android.com/studio/run/emulator-commandline
--- Edit ---
To avoid typing the -kernel argument every time, you can also copy the ~/Library/Android/sdk/system-images/android-16/default/armeabi-v7a/kernel-qemu file to ~/Library/Android/sdk/add-ons/addon-google_apis-google-16/images/armeabi-v7a.
Maybe it is the emulator tool path issue. Try to specify the full path of your emulator path.
Try the answer from here. Windows emulator.exe PANIC: Missing emulator engine program for 'x86' CPU