linux-user: refactor ipc syscall and support of semtimedop syscall

linux-user: refactor ipc syscall and support of semtimedop syscall

Refactoring ipc syscall for s390x and SPARC, so it matches glibc implementation

We should add support of semtimedop syscall as new version of glibc
2.31 uses semop based on semtimedop
(commit: https://gitlab.com/freedesktop-sdk/mirrors/sourceware/glibc/-/commit/765cdd0bffd77960ae852104fc4ea5edcdb8aed3 ).

Signed-off-by: Matus Kysel <mkysel@tachyum.com>
Message-Id: <20200626124612.58593-2-mkysel@tachyum.com>
Message-Id: <20200626124612.58593-3-mkysel@tachyum.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
[lv: merged PATCH 1 & 2 to avoid build break on PATCH 1]
Signed-off-by: Laurent Vivier <laurent@vivier.eu>