set to the clang wrapper that invokes clang for iOS. For example, this command runs
 all.bash on the iOS emulator:

	GOOS=ios GOARCH=amd64 CGO_ENABLED=1 CC_FOR_TARGET=$(pwd)/../misc/ios/clangwrap.sh ./all.bash

If CC_FOR_TARGET is not set when the toolchain is built (make.bash or all.bash), CC
can be set on the command line. For example,

	GOOS=ios GOARCH=amd64 CGO_ENABLED=1 CC=$(go env GOROOT)/misc/ios/clangwrap.sh go build

C compiler from the Android NDK. For example,

	CGO_ENABLED=1 \
	GOOS=android \
	GOARCH=arm64 \
	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