Keep list of uses sorted when building it.

runtime/vm/flow_graph_allocator.h

Index: runtime/vm/flow_graph_allocator.h
diff --git a/runtime/vm/flow_graph_allocator.h b/runtime/vm/flow_graph_allocator.h
index 013eb6f41d360f99cf5201b234b3888b320ada2c..8b106bd6640c85d269628600c5182383911f6509 100644
--- a/runtime/vm/flow_graph_allocator.h
+++ b/runtime/vm/flow_graph_allocator.h
@@ -558,8 +558,6 @@ class LiveRange : public ZoneAllocated {
       finger_() {
   }
 
-  static LiveRange* MakeTemp(intptr_t pos, Location* location_slot);
-
   intptr_t vreg() const { return vreg_; }
   Representation representation() const { return representation_; }
   LiveRange* next_sibling() const { return next_sibling_; }
@@ -588,15 +586,13 @@ class LiveRange : public ZoneAllocated {
 
   void AddSafepoint(intptr_t pos, LocationSummary* locs);
 
-  void AddUse(intptr_t pos, Location* location_slot);
+  UsePosition* AddUse(intptr_t pos, Location* location_slot);
   void AddHintedUse(intptr_t pos, Location* location_slot, Location* hint);
 
   void AddUseInterval(intptr_t start, intptr_t end);
 
   void Print();
 
-  void AssignLocation(UseInterval* use, Location loc);
-
   LiveRange* SplitAt(intptr_t pos);
 
   // A fast conservative check if the range might contain a given position