Fixes to kernel to get checkpoints to work again.

kern/kernel_stats.cc:
    Serialize idleProcess.
kern/system_events.cc:
    Remove the idle start event once it runs.

--HG--
extra : convert_revision : 05ac574558a88b86ccfce963e4ca9b037a1a8509

kern/kernel_stats.cc

@@ -294,6 +294,7 @@ Statistics::serialize(ostream &os)
 {
     int exemode = themode;
     SERIALIZE_SCALAR(exemode);
+    SERIALIZE_SCALAR(idleProcess);
 }
 
 void
@@ -301,6 +302,7 @@ Statistics::unserialize(Checkpoint *cp, const string &section)
 {
     int exemode;
     UNSERIALIZE_SCALAR(exemode);
+    UNSERIALIZE_SCALAR(idleProcess);
     themode = (cpu_mode)exemode;
 }
 

kern/system_events.cc

@@ -70,6 +70,7 @@ void
 IdleStartEvent::process(ExecContext *xc)
 {
     xc->kernelStats->setIdleProcess(xc->regs.ipr[AlphaISA::IPR_PALtemp23]);
+    remove();
 }
 
 void