Remove the unused HElementsKind instruction.

src/ia32/lithium-ia32.cc

Index: src/ia32/lithium-ia32.cc
diff --git a/src/ia32/lithium-ia32.cc b/src/ia32/lithium-ia32.cc
index d50313f88f3137ab5a40157a5f72b2542d1db551..b25cbc3942d25ea40b5a6663a94ab0faa821c613 100644
--- a/src/ia32/lithium-ia32.cc
+++ b/src/ia32/lithium-ia32.cc
@@ -1697,12 +1697,6 @@ LInstruction* LChunkBuilder::DoMapEnumLength(HMapEnumLength* instr) {
 }
 
 
-LInstruction* LChunkBuilder::DoElementsKind(HElementsKind* instr) {
-  LOperand* object = UseRegisterAtStart(instr->value());
-  return DefineAsRegister(new(zone()) LElementsKind(object));
-}
-
-
 LInstruction* LChunkBuilder::DoValueOf(HValueOf* instr) {
   LOperand* object = UseRegister(instr->value());
   LValueOf* result = new(zone()) LValueOf(object, TempRegister());