Image crashes on new ARM64 Macs

[robcast]

The current 3m-docker image built for x86_64 crashes on the new "Apple-Silicon" i.e. ARM64 Macs. The problem seems to lie with the QEMU-based emulation of the x86_64 binary of Java 8. I tested using the "M1 tech preview" (3.1.0 (60984)) version.

3M works fine using a native ARM64 image of Java 8. The problem is that Docker does not supply ARM64 builds for Java 8 in the default library version of OpenJDK (it starts at Java 11). There are older builds under arm64v8/8-jre so I patched the Dockerfile to be able to supply a different prefix when building: robcast@6765738 and uploaded new images: https://hub.docker.com/repository/docker/robcast/3m-docker

Ideally we could integrate the ARM64 image into your regular image as a multi-arch build but I have not found out how to do that yet...