Java 11 for iOS

[Johan Vos]

Hi,

Last week, I mirrored the Java 11 stabilization repository
http://hg.openjdk.java.net/jdk/jdk11 into a github repository
https://github.com/javafxports/openjdk-mobile11 which I forked at
https://github.com/johanvos/openjdk-mobile11 and where I created a branch
apply9diffs.

In that branch, I tried to build the SDK (Client VM + class libraries
including native libs). When running into issues, I first looked at how it
was solved in the Java 9 version (thanks again to Bob and Gary for those
patches).
I'm happy to announce that I just managed to build everything (libjvm.a,
almost all jmods and their required native implementations) for IOS x86-64.

The diff is remarkably small, see
https://github.com/javafxports/openjdk-mobile11/pull/1/files

Most of the diff is not touching any logic for other build targets at all.
iOS for arm64 and Android builds are still todo, but this already shows
that the core OpenJDK is in a pretty good shape to be the basis for mobile
java development.

- Johan