Get rid of the HInstanceSize instruction.

src/mips/lithium-mips.cc

Index: src/mips/lithium-mips.cc
diff --git a/src/mips/lithium-mips.cc b/src/mips/lithium-mips.cc
index bf18838836384f8f8556e2bf98d4a5143db17f0a..3af5c045f788e5ed239e7707c5ee054f95273f7b 100644
--- a/src/mips/lithium-mips.cc
+++ b/src/mips/lithium-mips.cc
@@ -1068,12 +1068,6 @@ 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());