RFR: Upstream merge jdk/jdk -> shenandoah/jdk 2018-07-27

[Roman Kennke]

Am 27.07.2018 um 00:31 schrieb Roman Kennke:
> This merges in tags jdk-12+3 and jdk-12+4, and adds corresponding
> shenandoah-jdk-12+3 and shenandoah-jdk-12+4 tags. The same 'precise'
> merging+tagging procedure as last time was used.
> 
> Only minor/trival merge conflicts arose and no significant (to
> Shenandoah) new features arrived.
> 
> List of stuff merged in:
> http://cr.openjdk.java.net/~rkennke/jdk-upstream-merge-2018-07-27/outgoint.txt
> 

Oh and it did not regress testing (locally at least)

Roman