ThreadState: initialize status to Halted in constructor.

This provides a common initial status for all threads independent
of CPU model (unlike the prior situation where CPUs initialized
threads to inconsistent states).
This mostly matters for SE mode; in FS mode, ISA-specific startupCPU()
methods generally handle boot-time initialization of thread contexts
(since the right thing to do is ISA-dependent).

src/cpu/inorder/cpu.cc

@@ -193,10 +193,6 @@ InOrderCPU::InOrderCPU(Params *params)
                     i, this->thread[i]);
             this->thread[i] = new Thread(this, i, params->workload[i],
                                          i);
-
-            // Start thread's off in "Suspended" status
-            this->thread[i]->setStatus(ThreadContext::Suspended);
-
         } else {
             //Allocate Empty thread so M5 can use later
             //when scheduling threads to CPU