Catch stream heisenbug, initialize scheduler IRQs before smp_init (), reduce stream max size

kernel/amd64/bootmain.c

@@ -78,6 +78,9 @@ void bootmain (void) {
   struct device* temp0 = device_find ("temp0");
   vfs_create_volume (thiscpu->kproc, &rctx, "temp", FS_FAT16, temp0, true);
 
+  irq_attach (&proc_irq_sched, NULL, SCHED_PREEMPT_TIMER);
+  irq_attach (&proc_irq_sched, NULL, CPU_REQUEST_SCHED);
+
   smp_init ();
 
   proc_init ();