inorder: resource scheduling backend

replace priority queue with vector of lists(1 list per stage) and place inside a class
so that we have more control of when an instruction uses a particular schedule entry
...
also, this is the 1st step toward making the InOrderCPU fully parameterizable. See the
wiki for details on this process

src/cpu/inorder/cpu.cc

@@ -1354,7 +1354,7 @@ InOrderCPU::cleanUpRemovedInsts()
         // Make Sure Resource Schedule Is Emptied Out
         ThePipeline::ResSchedule *inst_sched = &inst->resSched;
         while (!inst_sched->empty()) {
-            ThePipeline::ScheduleEntry* sch_entry = inst_sched->top();
+            ScheduleEntry* sch_entry = inst_sched->top();
             inst_sched->pop();
             delete sch_entry;
         }