[11] Request for sponsor to putback fix for JDK-8201509: Zero : S390 31bit (S390 and not _LP64) atomic_copy64 inline assembler is wrong

[Chris Phillips]

Hi,

I'd like find a JDK11 committer to sponsor and putback this
fix  :

JDK-8201509: Zero : S390 31bit (S390 and not _LP64) atomic_copy64 inline
assembler is wrong

Bug:
 https://bugs.openjdk.java.net/browse/JDK-8201509

WebRev:
 http://cr.openjdk.java.net/~chrisphi/JDK-8201509/webrev.3
Changeset:
 http://cr.openjdk.java.net/~chrisphi/JDK-8201509/webrev.3/jdk.changeset

Review thread:
http://mail.openjdk.java.net/pipermail/hotspot-dev/2018April/031626.html

Testing: Builds itself on s390 31bit with some other local patches to
avoid type mismatches.

Chris