Remove the unused HElementsKind instruction.

src/mips/lithium-mips.h

Index: src/mips/lithium-mips.h
diff --git a/src/mips/lithium-mips.h b/src/mips/lithium-mips.h
index 5250c63c450ec7bd11bbab4e2332268327f7a251..8dff399f27c05cc33e657b62d8cb834a94a5332b 100644
--- a/src/mips/lithium-mips.h
+++ b/src/mips/lithium-mips.h
@@ -91,7 +91,6 @@ class LCodeGen;
   V(Drop)                                       \
   V(Dummy)                                      \
   V(DummyUse)                                   \
-  V(ElementsKind)                               \
   V(ForInCacheArray)                            \
   V(ForInPrepareMap)                            \
   V(FunctionLiteral)                            \
@@ -1275,19 +1274,6 @@ class LMapEnumLength V8_FINAL : public LTemplateInstruction<1, 1, 0> {
 };
 
 
-class LElementsKind V8_FINAL : public LTemplateInstruction<1, 1, 0> {
- public:
-  explicit LElementsKind(LOperand* value) {
-    inputs_[0] = value;
-  }
-
-  LOperand* value() { return inputs_[0]; }
-
-  DECLARE_CONCRETE_INSTRUCTION(ElementsKind, "elements-kind")
-  DECLARE_HYDROGEN_ACCESSOR(ElementsKind)
-};
-
-
 class LValueOf V8_FINAL : public LTemplateInstruction<1, 1, 1> {
  public:
   LValueOf(LOperand* value, LOperand* temp) {