[aarch64-port-dev ] JDK 7 support in aarch64-port

[Aleksey Shipilev]

Hi,

I was wondering why these changes are in aarch64-port/jdk8u-shenandoah:
  https://hg.openjdk.java.net/aarch64-port/jdk8u-shenandoah/hotspot/rev/c40a7ed7df16
  https://hg.openjdk.java.net/aarch64-port/jdk8u-shenandoah/hotspot/rev/623e2e5f003a

They stick out in the difference against 8u upstream. It even adds another public method in API:
JVM_SetProtectionDomain. Do we actually use TARGET_JDK_VERSION=7 for building anywhere? If not,
should we revert this part?

-- 
Thanks,
-Aleksey