Add -reorder-basic-blocks option and fix nop insertion

src/IceClFlags.h

Index: src/IceClFlags.h
diff --git a/src/IceClFlags.h b/src/IceClFlags.h
index 97420eaa4c7ce870ef86eabde0a7d3215c13287a..b46935664739494839aa20d79f93ff842b00ede1 100644
--- a/src/IceClFlags.h
+++ b/src/IceClFlags.h
@@ -160,6 +160,11 @@ public:
     return RandomizeAndPoolImmediatesThreshold;
   }
 
+  bool shouldReorderBasicBlocks() const { return ReorderBasicBlocks; }
+  void setShouldReorderBasicBlocks(bool NewValue) {
+    ReorderBasicBlocks = NewValue;
+  }
+
   void setShouldReorderFunctions(bool Option) { ReorderFunctions = Option; }
   bool shouldReorderFunctions() const { return ReorderFunctions; }
 
@@ -236,6 +241,7 @@ private:
   bool PhiEdgeSplit;
   bool RandomNopInsertion;
   bool RandomRegAlloc;
+  bool ReorderBasicBlocks;
   bool ReorderFunctions;
   bool ReorderGlobalVariables;
   bool ReorderPooledConstants;