Add option to disable scheduling.

llvm-svn: 1973
diff --git a/llvm/lib/CodeGen/InstrSched/SchedPriorities.h b/llvm/lib/CodeGen/InstrSched/SchedPriorities.h
index 2d0bff9..c76bead 100644
--- a/llvm/lib/CodeGen/InstrSched/SchedPriorities.h
+++ b/llvm/lib/CodeGen/InstrSched/SchedPriorities.h
@@ -38,6 +38,7 @@
 
 enum SchedDebugLevel_t {
   Sched_NoDebugInfo,
+  Sched_Disable,
   Sched_PrintMachineCode, 
   Sched_PrintSchedTrace,
   Sched_PrintSchedGraphs,