[intrinsics] Kill the %_IsMinusZero intrinsic.

src/crankshaft/x64/lithium-x64.cc

Index: src/crankshaft/x64/lithium-x64.cc
diff --git a/src/crankshaft/x64/lithium-x64.cc b/src/crankshaft/x64/lithium-x64.cc
index 2a32900a404521b4e2612a1be2e3ca319f798390..171a58115ae9c58499725b8d151fe5ce56875a03 100644
--- a/src/crankshaft/x64/lithium-x64.cc
+++ b/src/crankshaft/x64/lithium-x64.cc
@@ -1702,13 +1702,6 @@ LInstruction* LChunkBuilder::DoCompareHoleAndBranch(
 }
 
 
-LInstruction* LChunkBuilder::DoCompareMinusZeroAndBranch(
-    HCompareMinusZeroAndBranch* instr) {
-  LOperand* value = UseRegister(instr->value());
-  return new(zone()) LCompareMinusZeroAndBranch(value);
-}
-
-
 LInstruction* LChunkBuilder::DoIsStringAndBranch(HIsStringAndBranch* instr) {
   DCHECK(instr->value()->representation().IsTagged());
   LOperand* value = UseRegisterAtStart(instr->value());