[intrinsics] Kill the %_IsMinusZero intrinsic.

src/crankshaft/hydrogen-instructions.h

Index: src/crankshaft/hydrogen-instructions.h
diff --git a/src/crankshaft/hydrogen-instructions.h b/src/crankshaft/hydrogen-instructions.h
index 53e8b0f645006afddd10bcadb9b17679eb676742..624bbad1b79c93419efcac83abc4d39188163246 100644
--- a/src/crankshaft/hydrogen-instructions.h
+++ b/src/crankshaft/hydrogen-instructions.h
@@ -79,7 +79,6 @@ class LChunkBuilder;
   V(CompareNumericAndBranch)                  \
   V(CompareHoleAndBranch)                     \
   V(CompareGeneric)                           \
-  V(CompareMinusZeroAndBranch)                \
   V(CompareObjectEqAndBranch)                 \
   V(CompareMap)                               \
   V(Constant)                                 \
@@ -4345,27 +4344,6 @@ class HCompareHoleAndBranch final : public HUnaryControlInstruction {
 };
 
 
-class HCompareMinusZeroAndBranch final : public HUnaryControlInstruction {
- public:
-  DECLARE_INSTRUCTION_FACTORY_P1(HCompareMinusZeroAndBranch, HValue*);
-
-  void InferRepresentation(HInferRepresentationPhase* h_infer) override;
-
-  Representation RequiredInputRepresentation(int index) override {
-    return representation();
-  }
-
-  bool KnownSuccessorBlock(HBasicBlock** block) override;
-
-  DECLARE_CONCRETE_INSTRUCTION(CompareMinusZeroAndBranch)
-
- private:
-  explicit HCompareMinusZeroAndBranch(HValue* value)
-      : HUnaryControlInstruction(value, NULL, NULL) {
-  }
-};
-
-
 class HCompareObjectEqAndBranch : public HTemplateControlInstruction<2, 2> {
  public:
   DECLARE_INSTRUCTION_FACTORY_P2(HCompareObjectEqAndBranch, HValue*, HValue*);