s390x: Fix BZ 496950

s390x: Fix BZ 496950

Adding a new hardware capability requires changes in several places.
Generally for a new FOO hardware capability:
- add VEX_HWCAPS_S390X_FOO and update VEX_HWCAPS_S390X_ALL in libvex.h
- test the corresponding facility bit in m_machine.c
- add s390_host_has_foo in host_s390_defs.h
- if an insn requiring FOO cannot be implemented on the host by other means
  - add EmFail_S390X_foo in libvex_emnote.h
- handle EmFail_S390X_foo in main_main.c
- update function show_hwcaps_s390x

Occasionally something gets forgotten and this patch adds the forgotten
pieces.
Also add new hardware capabilities vxe2, vxd, msa, msa4, msa8, msa9

Fixes: https://bugs.kde.org/show_bug.cgi?id=496950