Eliminate temporary locals for some expressions

runtime/vm/flow_graph_optimizer.cc

Index: runtime/vm/flow_graph_optimizer.cc
===================================================================
--- runtime/vm/flow_graph_optimizer.cc	(revision 23243)
+++ runtime/vm/flow_graph_optimizer.cc	(working copy)
@@ -5061,6 +5061,18 @@
 }
 
 
+void ConstantPropagator::VisitPushTemp(PushTempInstr* instr) {
+  // Instruction is eliminated when translating to SSA.
+  UNREACHABLE();
+}
+
+
+void ConstantPropagator::VisitDropTemps(DropTempsInstr* instr) {
+  // Instruction is eliminated when translating to SSA.
+  UNREACHABLE();
+}
+
+
 void ConstantPropagator::VisitStoreLocal(StoreLocalInstr* instr) {
   // Instruction is eliminated when translating to SSA.
   UNREACHABLE();