x/sys: new syscall.PtraceInterrupt for linux #34755

A new func inside syscall to expose the use of PTRACE_INTERRUPT.

PTRACE_INTERRUPT (since Linux 3.4)
Stop a tracee. If the tracee is running or sleeping in kernel
space and PTRACE_SYSCALL is in effect, the system call is
interrupted and syscall-exit-stop is reported. (The inter‐
rupted system call is restarted when the tracee is restarted.)
If the tracee was already stopped by a signal and PTRACE_LIS‐
TEN was sent to it, the tracee stops with PTRACE_EVENT_STOP
and WSTOPSIG(status) returns the stop signal. If any other
ptrace-stop is generated at the same time (for example, if a
signal is sent to the tracee), this ptrace-stop happens. If
none of the above applies (for example, if the tracee is run‐
ning in user space), it stops with PTRACE_EVENT_STOP with
WSTOPSIG(status) == SIGTRAP. PTRACE_INTERRUPT only works on
tracees attached by PTRACE_SEIZE.
source: ptrace in Linux

The flag already exists in the codebase: