Add support for XMM registers in SSA code generation pipeline.

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 b83b16b7cd1d5815a22b121a345fcdb58c822b9c..dece2dc3e31656d96d613f973e2adc21e3a5e2de 100644
--- a/runtime/vm/flow_graph_optimizer.h
+++ b/runtime/vm/flow_graph_optimizer.h
@@ -14,8 +14,9 @@ template <typename T> class GrowableArray;
 
 class FlowGraphOptimizer : public FlowGraphVisitor {
  public:
-  explicit FlowGraphOptimizer(const FlowGraph& flow_graph)
-      : FlowGraphVisitor(flow_graph.reverse_postorder()) {}
+  explicit FlowGraphOptimizer(FlowGraph* flow_graph)
+      : FlowGraphVisitor(flow_graph->reverse_postorder()),
+        flow_graph_(flow_graph) { }
   virtual ~FlowGraphOptimizer() {}
 
   void ApplyICData();
@@ -47,6 +48,12 @@ class FlowGraphOptimizer : public FlowGraphVisitor {
 
   bool TryInlineInstanceMethod(BindInstr* instr, InstanceCallComp* comp);
 
+  Value* InsertBefore(Instruction* instr, Computation* comp, Environment* env);
+
+  BindInstr* InsertAfter(Instruction* instr, Computation* comp);
+
+  FlowGraph* flow_graph_;
+
   DISALLOW_COPY_AND_ASSIGN(FlowGraphOptimizer);
 };