Unboxed Float64x2 fields and some misc fixes

runtime/vm/flow_graph_optimizer.cc

Index: runtime/vm/flow_graph_optimizer.cc
diff --git a/runtime/vm/flow_graph_optimizer.cc b/runtime/vm/flow_graph_optimizer.cc
index 83d9383aff76e578dc31ee833687d92bd5d06576..01a56ad6cb11d718277611b26aeb085d122986e7 100644
--- a/runtime/vm/flow_graph_optimizer.cc
+++ b/runtime/vm/flow_graph_optimizer.cc
@@ -1960,6 +1960,8 @@ bool FlowGraphOptimizer::TryReplaceWithBinaryOp(InstanceCallInstr* call,
         operands_type = kDoubleCid;
       } else if (HasOnlyTwoOf(ic_data, kFloat32x4Cid)) {
         operands_type = kFloat32x4Cid;
+      } else if (HasOnlyTwoOf(ic_data, kFloat64x2Cid)) {
+        operands_type = kFloat64x2Cid;
       } else {
         return false;
       }
@@ -1970,6 +1972,8 @@ bool FlowGraphOptimizer::TryReplaceWithBinaryOp(InstanceCallInstr* call,
         operands_type = kDoubleCid;
       } else if (HasOnlyTwoOf(ic_data, kFloat32x4Cid)) {
         operands_type = kFloat32x4Cid;
+      } else if (HasOnlyTwoOf(ic_data, kFloat64x2Cid)) {
+        operands_type = kFloat64x2Cid;
       } else {
         return false;
       }