Convert diamond shaped control flow into a single conditional instruction.

runtime/vm/flow_graph_optimizer.h

Index: runtime/vm/flow_graph_optimizer.h
diff --git a/runtime/vm/flow_graph_optimizer.h b/runtime/vm/flow_graph_optimizer.h
index f2d4e386de80bd2c43f913e6a94e5e2fc6935c4d..1b48ac2c1eef2bec18721578fc6afde7ffe76ad9 100644
--- a/runtime/vm/flow_graph_optimizer.h
+++ b/runtime/vm/flow_graph_optimizer.h
@@ -304,6 +304,15 @@ class BranchSimplifier : public AllStatic {
 };
 
 
+// Rewrite diamond control flow patterns that materialize values to use more
+// efficient branchless code patterns if such are supported on the current
+// platform.
+class IfConverter : public AllStatic {
+ public:
+  static void Simplify(FlowGraph* flow_graph);
+};
+
+
 }  // namespace dart
 
 #endif  // VM_FLOW_GRAPH_OPTIMIZER_H_