[intrinsics] Kill the %_IsMinusZero intrinsic.

src/crankshaft/mips/lithium-mips.cc

Index: src/crankshaft/mips/lithium-mips.cc
diff --git a/src/crankshaft/mips/lithium-mips.cc b/src/crankshaft/mips/lithium-mips.cc
index 3259d1c8105eb3583478929d0a84e07ea6a77ae0..027021177daa7ab4080926607157fc578eb37045 100644
--- a/src/crankshaft/mips/lithium-mips.cc
+++ b/src/crankshaft/mips/lithium-mips.cc
@@ -1690,14 +1690,6 @@ LInstruction* LChunkBuilder::DoCompareHoleAndBranch(
 }
 
 
-LInstruction* LChunkBuilder::DoCompareMinusZeroAndBranch(
-    HCompareMinusZeroAndBranch* instr) {
-  LOperand* value = UseRegister(instr->value());
-  LOperand* scratch = TempRegister();
-  return new(zone()) LCompareMinusZeroAndBranch(value, scratch);
-}
-
-
 LInstruction* LChunkBuilder::DoIsStringAndBranch(HIsStringAndBranch* instr) {
   DCHECK(instr->value()->representation().IsTagged());
   LOperand* temp = TempRegister();