Get rid of the HInstanceSize instruction.

src/arm/lithium-arm.cc

Index: src/arm/lithium-arm.cc
diff --git a/src/arm/lithium-arm.cc b/src/arm/lithium-arm.cc
index 6c193fe013fdc46c9d73abc02c8b264a2468e07c..ea33418fae1ed39ce47511239d3b81a61ef7d711 100644
--- a/src/arm/lithium-arm.cc
+++ b/src/arm/lithium-arm.cc
@@ -1079,12 +1079,6 @@ LInstruction* LChunkBuilder::DoInstanceOfKnownGlobal(
 }
 
 
-LInstruction* LChunkBuilder::DoInstanceSize(HInstanceSize* instr) {
-  LOperand* object = UseRegisterAtStart(instr->object());
-  return DefineAsRegister(new(zone()) LInstanceSize(object));
-}
-
-
 LInstruction* LChunkBuilder::DoWrapReceiver(HWrapReceiver* instr) {
   LOperand* receiver = UseRegisterAtStart(instr->receiver());
   LOperand* function = UseRegisterAtStart(instr->function());