RFC/RFR: Pick up jdk-11.0.3+4 to sh/jdk11

[Aleksey Shipilev]

Upstream^W We have pushed the jdk-11.0.3+4 tag upstream to jdk-updates/jdk11u. Let's pick it up to
sh/jdk11. The merge is not trivial, because AArch64 changes are in the same files.

Summary of changes:
  http://cr.openjdk.java.net/~shade/shenandoah/merges/jdk11-11.0.3%2b4/changesets.txt

Webrev:
  http://cr.openjdk.java.net/~shade/shenandoah/merges/jdk11-11.0.3%2b4/webrev.01/

You can cross-reference the changes with the changes in upstream:
  http://hg.openjdk.java.net/jdk-updates/jdk11u/rev/43d6759c3b2e
  http://hg.openjdk.java.net/jdk-updates/jdk11u/rev/33c0eba993dd
  http://hg.openjdk.java.net/jdk-updates/jdk11u/rev/e58b6d05d723
  http://hg.openjdk.java.net/jdk-updates/jdk11u/rev/0402d1e99f13
  http://hg.openjdk.java.net/jdk-updates/jdk11u/rev/1bf93f4064ac
  http://hg.openjdk.java.net/jdk-updates/jdk11u/rev/b3857fc867d7

The plan is to push this merge, run it through nightlies and then tag it shenandoah-jdk-11.0.3+4.

Testing: x86_64 hotspot_gc_shenandoah {fastdebug,release}, AArch64 build {fastdebug, release}

Thanks,
-Aleksey