RFR: JEP draft for Linux/s3990x port

[Volker Simonis]

Hi,

can you please review and endorse the following draft JEP for the
integration of the Linux/s390x port into the jkd9 master repository:

https://bugs.openjdk.java.net/browse/JDK-8166730

As detailed in the JEP, the Linux/s390x requires very few shared
changes and we therefore don't foresee any impact on the existing
platforms at all. Following you can find a short description of the
planned changes:

hotspot:
=======

Out for review:
8166560: [s390] Basic enablement of s390 port.
http://cr.openjdk.java.net/~goetz/wr16/8166560-basic_s390/hotspot.wr01/

Reviewed:
8166562: C2: Suppress relocations in scratch emit.
http://cr.openjdk.java.net/~goetz/wr16/8166562-scratch_emit/webrev.01/

Will send RFR soon (depends on 8166560):
8166561: [s390] Adaptions needed for s390 port in C1 and C2.
http://cr.openjdk.java.net/~goetz/wr16/8166562-scratch_emit/webrev.01

We are still investigating the need of these shared changes:
http://cr.openjdk.java.net/~goetz/wr16/s390x_patch_queue/hotspot/9000011-pass_PC_to_retAddrOffset.patch
http://cr.openjdk.java.net/~goetz/wr16/s390x_patch_queue/hotspot/9000016-constant_table_offset.patch

And finally the patch with the s390x-only platform files. We are still
editing these to get them into OpenJdk style and shape.
Hotspot passes most jck, jtreg and spec tests with these.
http://cr.openjdk.java.net/~goetz/wr16/s390x_patch_queue/hotspot/9000101-zFiles.patch

top-level repository:
===============

The following is just adding some s390x specific compiler flags to flags.m4
8166800: [s390] Top-level build changes required for Linux/s390x
https://bugs.openjdk.java.net/browse/JDK-8166800

jdk repository:
============

This one just adds a new jvm.cfg file for s390x
8166801: [s390] Add jvm.cfg file for Linux/s390x
https://bugs.openjdk.java.net/browse/JDK-8166801


And finally we plan to do one more change which fixes the jtreg test
on Linux/s390x. But this is mainly for the correct detection of the
platform and for excluding the tests which are not appropriate for
s390x.

Thank you and best regards,
Volker