Rebuilt for IMA sigs, glibc 2.34, aarch64 flags

Rebuilt for RHEL 9 BETA on Apr 15th 2021. Related: rhbz#1947937

Remove unused scriptlets

Fix the messed scriptlets

Rebuilt for https://fedoraproject.org/wiki/Fedora_34_Mass_Rebuild

Sync with rhel 8.3 + cleanup
Add new subpackages - z{14,15}
Unlike in rhel8, the base subpackage still needs to be build for z12.
Covscan related bugfixes
Spec and git cleanup (remove unused patches/sources)

Rebuilt for https://fedoraproject.org/wiki/Fedora_33_Mass_Rebuild

Drop IBM z10 and z196 subpackages
s390 is now optimized for z12

Fix compatibility with gcc 10
Sync compiler/linker flags with RHEL