Switch to Java 11

[dmlloyd]

This is the blanket issue to cover switching to Java 11. Here's the check list:

• Introduce an artifact which contains the contents of the com.oracle.svm.driver package from the SubstrateVM build (the default coordinates are com.oracle.substratevm:svm-driver; use mx maven-install to install it locally after checking out & building with the vm-1.0.0-rc11 tag under Java 11)
• Make the native image generator depend on this artifact
• Change org.jboss.shamrock.creator.phase.nativeimage.NativeImagePhase to use com.oracle.svm.driver.NativeImage from the driver artifact directly for normal builds, and via container execution of java (11) for container builds
• Delete checks for GRAALVM_HOME
• Update POMs to require Java 11 (use <release>11</release> in the compiler plugin, not -source/-target)
• Full integration test run on Linux & Windows

Note that some of these steps will have to change if the class loading changes come in first.

[dmlloyd]

The alternative would be to require some external native-image package to be installed.

[Sanne]

Also before we move on to require Java 11 as base, we should start having CI monitor that what we have today is actually compatible with Java 11 - at least in JVM mode.

[bobmcwhirter]

oracle/graal#1392

[gsmet]

@dmlloyd should I close this one? Looks like the effort is now made in separate issues specific to GraalVM?

[dmlloyd]

Yep this is out of date.

[dmlloyd]

Please see #5691 for the up-to-date migration steps.