Don't create dummy uses for control dependencies.

src/x64/lithium-x64.cc

Index: src/x64/lithium-x64.cc
diff --git a/src/x64/lithium-x64.cc b/src/x64/lithium-x64.cc
index 4ef7082eaee2c8161416c8ee4a3da5101650277d..5c3fd709800fbfdab1eb25c18ee8a54f6a3d56c5 100644
--- a/src/x64/lithium-x64.cc
+++ b/src/x64/lithium-x64.cc
@@ -857,10 +857,12 @@ void LChunkBuilder::VisitInstruction(HInstruction* current) {
     if (current->OperandCount() == 0) {
       instr = DefineAsRegister(new(zone()) LDummy());
     } else {
+      ASSERT(!current->OperandAt(0)->IsControlInstruction());
       instr = DefineAsRegister(new(zone())
           LDummyUse(UseAny(current->OperandAt(0))));
     }
     for (int i = 1; i < current->OperandCount(); ++i) {
+      if (current->OperandAt(i)->IsControlInstruction()) continue;
       LInstruction* dummy =
           new(zone()) LDummyUse(UseAny(current->OperandAt(i)));
       dummy->set_hydrogen_value(current);