CC_FOR_TARGET=$NDK/toolchains/llvm/prebuilt/linux-x86_64/bin/aarch64-linux-android21-clang \
	./all.bash

To run tests on the Android device, add the bin directory to PATH so the
go tool can find the go_android_$GOARCH_exec wrapper generated by
make.bash. For example, to run the go1 benchmarks

	export PATH=$GOROOT/bin:$PATH
	cd $GOROOT/test/bench/go1/

To use the go tool to run individual programs and tests, put $GOROOT/bin into PATH to ensure
the go_ios_$GOARCH_exec wrapper is found. For example, to run the archive/tar tests:

	export PATH=$GOROOT/bin:$PATH
	GOOS=ios GOARCH=amd64 CGO_ENABLED=1 go test archive/tar

The go_ios_exec wrapper uses GOARCH to select the emulator (amd64) or the device (arm64).