ptrace: add PTRACE_GET_SYSCALL_INFO request

procd since 3e88c6f2b179 ("jail/seccomp: add support for aarch64") for aarch64 uses PTRACE_GET_SYSCALL_INFO call.

PTRACE_GET_SYSCALL_INFO was added in kernel 5.3.

This backport to kernel 4.19 allows ptrace to compile.

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