It should be possible to build the native jdk libs [in the head of openjdk/mobile] for mobile systems (android/ios).
This is only one piece in the total puzzle for running Java apps on mobile devices, but having this as a separate issue (which can be fixed relatively easily) makes it easier to create and tackle other issues.
As a result of this issues being fixed, it should be possible to create libjava.a, libnet.a etc for android/ios.