Don't insert HDummyUses for control instructions

src/hydrogen.cc

Index: src/hydrogen.cc
diff --git a/src/hydrogen.cc b/src/hydrogen.cc
index 3423d4b288a89c170abd41b4980188fcac2b24fc..a4578ee3dfa5324e94cdd9ae32c2b08ffd9b7852 100644
--- a/src/hydrogen.cc
+++ b/src/hydrogen.cc
@@ -1303,6 +1303,12 @@ void HGraph::NullifyUnreachableInstructions() {
             }
             continue;
           }
+          if (operand->IsControlInstruction()) {
+            // Inserting a dummy use for a value that's not defined anywhere
+            // will fail. Some instructions define fake inputs on such
+            // values as control flow dependencies.
+            continue;
+          }
           HDummyUse* dummy = new(zone()) HDummyUse(operand);
           dummy->InsertBefore(instr);
           last_dummy = dummy;