Remove HIsNilAndBranch (it's now unused)

src/hydrogen-instructions.h

Index: src/hydrogen-instructions.h
diff --git a/src/hydrogen-instructions.h b/src/hydrogen-instructions.h
index a290628d8f65dd168c66475197ec3466f4f413f7..ca53b0584206c4c05c6861474fd1806963df4a99 100644
--- a/src/hydrogen-instructions.h
+++ b/src/hydrogen-instructions.h
@@ -127,7 +127,6 @@ class LChunkBuilder;
   V(InstanceSize)                              \
   V(InvokeFunction)                            \
   V(IsConstructCallAndBranch)                  \
-  V(IsNilAndBranch)                            \
   V(IsObjectAndBranch)                         \
   V(IsStringAndBranch)                         \
   V(IsSmiAndBranch)                            \
@@ -3921,31 +3920,6 @@ class HCompareConstantEqAndBranch: public HUnaryControlInstruction {
 };
 
 
-class HIsNilAndBranch: public HUnaryControlInstruction {
- public:
-  HIsNilAndBranch(HValue* value, EqualityKind kind, NilValue nil)
-      : HUnaryControlInstruction(value, NULL, NULL), kind_(kind), nil_(nil) { }
-
-  EqualityKind kind() const { return kind_; }
-  NilValue nil() const { return nil_; }
-
-  virtual void PrintDataTo(StringStream* stream);
-
-  virtual Representation RequiredInputRepresentation(int index) {
-    return Representation::Tagged();
-  }
-  virtual Representation observed_input_representation(int index) {
-    return Representation::Tagged();
-  }
-
-  DECLARE_CONCRETE_INSTRUCTION(IsNilAndBranch)
-
- private:
-  EqualityKind kind_;
-  NilValue nil_;
-};
-
-
 class HIsObjectAndBranch: public HUnaryControlInstruction {
  public:
   explicit HIsObjectAndBranch(HValue* value)