This update for zlib fixes the following issues:

- Update the s390 patchset. (bsc#1137624)
- Tweak zlib-power8 to have type of crc32_vpmsum conform to usage. (bsc#1141059)
- Use FAT LTO objects in order to provide proper static library.
- Do not enable the previous patchset on s390 but just s390x. (bsc#1137624)
- Add patchset for s390 improvements. (jsc#SLE-5807, bsc#1136717)

This update was imported from the SUSE:SLE-15:Update update project.