Weaken a bogus assertion in use list verification.

runtime/vm/flow_graph.cc

Index: runtime/vm/flow_graph.cc
diff --git a/runtime/vm/flow_graph.cc b/runtime/vm/flow_graph.cc
index 390e3d746b08fea3a8a814deba862c5d9ce7654e..e7598ac0e07aabda2dc6ecec5435d37cd7eff979 100644
--- a/runtime/vm/flow_graph.cc
+++ b/runtime/vm/flow_graph.cc
@@ -131,7 +131,7 @@ static void VerifyUseListsInInstruction(Instruction* instr) {
   for (intptr_t i = 0; i < instr->InputCount(); ++i) {
     Value* use = instr->InputAt(i);
     ASSERT(use->definition() != NULL);
-    ASSERT(use->definition() != instr);
+    ASSERT((use->definition() != instr) || use->definition()->IsPhi());
     ASSERT(use->instruction() == instr);
     ASSERT(use->use_index() == i);
     ASSERT(!FLAG_verify_compiler ||
@@ -142,7 +142,7 @@ static void VerifyUseListsInInstruction(Instruction* instr) {
     for (Environment::DeepIterator it(instr->env()); !it.Done(); it.Advance()) {
       Value* use = it.CurrentValue();
       ASSERT(use->definition() != NULL);
-      ASSERT(use->definition() != instr);
+      ASSERT((use->definition() != instr) || use->definition()->IsPhi());
       ASSERT(use->instruction() == instr);
       ASSERT(use->use_index() == use_index++);
       ASSERT(!FLAG_verify_compiler ||