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

src/hydrogen.h

Index: src/hydrogen.h
diff --git a/src/hydrogen.h b/src/hydrogen.h
index 0837bf9634e33cc088a7a8dea90e479161c65902..ef61bffeb006638195df1768dc069cac4c8fa29c 100644
--- a/src/hydrogen.h
+++ b/src/hydrogen.h
@@ -355,6 +355,14 @@ class HGraph: public ZoneObject {
     use_optimistic_licm_ = value;
   }
 
+  bool has_soft_deoptimize() {
+    return has_soft_deoptimize_;
+  }
+
+  void set_has_soft_deoptimize(bool value) {
+    has_soft_deoptimize_ = value;
+  }
+
   void MarkRecursive() {
     is_recursive_ = true;
   }
@@ -377,6 +385,7 @@ class HGraph: public ZoneObject {
                               int32_t integer_value);
 
   void MarkAsDeoptimizingRecursively(HBasicBlock* block);
+  void NullifyUnreachableInstructions();
   void InsertTypeConversions(HInstruction* instr);
   void PropagateMinusZeroChecks(HValue* value, BitVector* visited);
   void RecursivelyMarkPhiDeoptimizeOnUndefined(HPhi* phi);
@@ -414,6 +423,7 @@ class HGraph: public ZoneObject {
 
   bool is_recursive_;
   bool use_optimistic_licm_;
+  bool has_soft_deoptimize_;
   int type_change_checksum_;
 
   DISALLOW_COPY_AND_ASSIGN(HGraph);
@@ -956,6 +966,8 @@ class HOptimizedGraphBuilder: public HGraphBuilder, public AstVisitor {
 
   bool inline_bailout() { return inline_bailout_; }
 
+  void AddSoftDeoptimize();
+
   // Bailout environment manipulation.
   void Push(HValue* value) { environment()->Push(value); }
   HValue* Pop() { return environment()->Pop(); }