Make precompiler work with product mode.

runtime/vm/block_scheduler.cc

Index: runtime/vm/block_scheduler.cc
diff --git a/runtime/vm/block_scheduler.cc b/runtime/vm/block_scheduler.cc
index 5b3d78d8f59941cb3ead384f10552053bcbc4fc0..bc9885dcecf9e2ae463c8a6a7af18bba3273ac6b 100644
--- a/runtime/vm/block_scheduler.cc
+++ b/runtime/vm/block_scheduler.cc
@@ -12,7 +12,7 @@
 namespace dart {
 
 static intptr_t GetEdgeCount(const Array& edge_counters, intptr_t edge_id) {
-  if (!FLAG_emit_edge_counters) {
+  if (!FLAG_reorder_basic_blocks) {
     // Assume everything was visited once.
     return 1;
   }
@@ -53,7 +53,7 @@ static void SetEdgeWeight(BlockEntryInstr* block,
 
 
 void BlockScheduler::AssignEdgeWeights() const {
-  if (!FLAG_emit_edge_counters) {
+  if (!FLAG_reorder_basic_blocks) {
     return;
   }