zlib bundling

[pshipton]

Copied from internal issue. The Adoptium pipelines started bundling zlib on all versions, all platforms. Semeru backed out this change. The following table shows what Semeru did for the 0.40 release.

Platform	8	11	17
aix	system	system	system
alinux	bundled	system	system
amac	-	system	system
xlinux	bundled	system	system
plinux	bundled	system	system
win 32	bundled	-	-
win	bundled	bundled	bundled
xmac	system	system	system
zlinux	bundled	system	system
z/OS	bundled	bundled	bundled

There is also https://bugs.openjdk.org/browse/JDK-8286623 which modifies 17.0.9 to use bundled for amac. Backport this to jdk11 via ibmruntimes/openj9-openjdk-jdk11#705.

Here is some of the Adoptium conversation. They also held meeting(s) to discuss, so there may be more details not captured in issues/PRs.
adoptium/temurin-build#1951
adoptium/temurin-build#3399
adoptium/temurin-build#3459

[pshipton]

@joransiu mentioned

For zLinux, the system zlib on the various distros have been updated with patches to exploit the on-chip integrated zEDC compression engine introduced on z15 and newer hardware -- it delivers up to 15x faster file compression and up to 100x in-memory compression for the java/util/zip/GZip* APIs. I don't believe the vanilla zlib has these changes.

@zl-wang mentioned

Post-POWER8, there is a GZIP hardware accelerator on each chip. There is a separate system zlib shipped with post-AIX7.2 TL4 (install explicitly) and RHEL9.1 (download/install IBM's AdvancedToolChain) respectively exploiting that accelerator. In order to use that zlib by default, we need to change LIBPATH on AIX or LD_LIBRARY_PATH on Linux respectively to point to that separate installation directory. It has similar performance benefit as above.

OpenJ9 builds modify the LIBPATH on AIX, but not yet on Linux.

[pshipton]

Created ibmruntimes/openj9-openjdk-jdk8#692 to use the system zlib on jdk8 Linux platforms to be consistent with jdk11+.