Implement streams IPC mechanism

libsystem/system.c

@@ -106,3 +106,11 @@ int exec_partial (const char* volume, const char* path) {
 int exec_partial_fini (int pid) { return (int)do_syscall (SYS_EXEC_PARTIAL_FINI, pid); }
 
 int get_self_pid (void) { return (int)do_syscall (SYS_GET_SELF_PID, 0); }
+
+int stream_write (int pgid, int rid, void* buffer, size_t size) {
+  return (int)do_syscall (SYS_STREAM_WRITE, pgid, rid, buffer, size);
+}
+
+int stream_read (int pgid, int rid, void* buffer, size_t size) {
+  return (int)do_syscall (SYS_STREAM_READ, pgid, rid, buffer, size);
+}