Don't create dummy uses for control dependencies.

src/ia32/lithium-ia32.cc

Index: src/ia32/lithium-ia32.cc
diff --git a/src/ia32/lithium-ia32.cc b/src/ia32/lithium-ia32.cc
index 80e3d4ad7e990bd0802b0a33a5e4b54aa4dee1e9..d50313f88f3137ab5a40157a5f72b2542d1db551 100644
--- a/src/ia32/lithium-ia32.cc
+++ b/src/ia32/lithium-ia32.cc
@@ -911,10 +911,12 @@ 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);