hg: jdk-updates/jdk11u-dev: 8218063: JDK-8218060 breaks build for S390

[matthias.baesken at sap.com]

Changeset: 6f72ae155396
Author:    tschatzl
Date:      2019-01-30 17:02 +0100
URL:       http://hg.openjdk.java.net/jdk-updates/jdk11u-dev/rev/6f72ae155396

8218063: JDK-8218060 breaks build for S390
Summary: Reinstated function removed by JDK-8218060 and properly ifdef'ed it.
Reviewed-by: shade, eosterlund

! src/hotspot/os/linux/os_linux.cpp