Eliminate temporary locals for some expressions

runtime/vm/flow_graph_type_propagator.cc

Index: runtime/vm/flow_graph_type_propagator.cc
===================================================================
--- runtime/vm/flow_graph_type_propagator.cc	(revision 23243)
+++ runtime/vm/flow_graph_type_propagator.cc	(working copy)
@@ -857,6 +857,16 @@
 }
 
 
+CompileType PushTempInstr::ComputeType() const {
+  return CompileType::Dynamic();
+}
+
+
+CompileType DropTempsInstr::ComputeType() const {
+  return CompileType::Dynamic();
+}
+
+
 CompileType* StoreLocalInstr::ComputeInitialType() const {
   // Returns stored value.
   return value()->Type();