PC(MacOS，Ubuntu): $./scripts/build.sh, target libraries are in build/sysroot/{Darwin,Linux}/x86_64/lib/.
Android: $./scripts/build.sh -f Android, target libraries are in build/sysroot/Android/armeabi-v7a/lib/.
iOS: $./scripts/build.sh -f iOS, target libraries are in build/sysroot/iOS/arm64/lib/.