Don't emit code for instructions that are hiding behind an HSoftDeoptimize

src/x64/lithium-x64.h

Index: src/x64/lithium-x64.h
diff --git a/src/x64/lithium-x64.h b/src/x64/lithium-x64.h
index f5f0250abd573d930750b7c501bf5c05ff7e77bd..24f5b271d91ad3ddb6df10d208b35ea9b7a021c4 100644
--- a/src/x64/lithium-x64.h
+++ b/src/x64/lithium-x64.h
@@ -93,6 +93,7 @@ class LCodeGen;
   V(Deoptimize)                                 \
   V(DivI)                                       \
   V(DoubleToI)                                  \
+  V(DummyUse)                                   \
   V(ElementsKind)                               \
   V(FastLiteral)                                \
   V(FixedArrayBaseLength)                       \
@@ -404,6 +405,15 @@ class LLazyBailout: public LTemplateInstruction<0, 0, 0> {
 };
 
 
+class LDummyUse: public LTemplateInstruction<1, 1, 0> {
+ public:
+  explicit LDummyUse(LOperand* value) {
+    inputs_[0] = value;
+  }
+  DECLARE_CONCRETE_INSTRUCTION(DummyUse, "dummy-use")
+};
+
+
 class LDeoptimize: public LTemplateInstruction<0, 0, 0> {
  public:
   DECLARE_CONCRETE_INSTRUCTION(Deoptimize, "deoptimize")