nx_kill_portable.nx

nx_kill_portable.nx -- kill(2) that works under BOTH compiler lanes. nx_syscalls' nx_kill hardcodes rv64 129 and relies on the SOVEREIGN compiler's rv64->x86 __syscall translation (129->62). The C-bootstrap compiler has NO translator, so 129 hits x86 rt_sigqueueinfo and fails silently -- gates hung on wait4 of children that never died, daemons leaked after every teardown (landmine #5, 2026-06-10). This helper uses the @ifdef pattern (same as SYS_GETDENTS64) so the kg lane emits the raw x86 number. SOVEREIGN-RE-GATE NOTE: 62 collides with rv64 lseek in the translator -- when the compiler lane re-blesses, either the translator learns to skip translation under TARGET_X86_64 or this helper switches back to 129 there. Tracked in the landmine doc. license_tier: ORIGINAL