[turbofan] Revert "Avoid overflow checks on SpeculativeNumberAdd/Subtract/Multiply."

src/compiler/representation-change.h

Index: src/compiler/representation-change.h
diff --git a/src/compiler/representation-change.h b/src/compiler/representation-change.h
index ebe948eeeeb3202db7fb85a40649749c876e36f3..fbb4cb5c95649037e02432056242ace665533529 100644
--- a/src/compiler/representation-change.h
+++ b/src/compiler/representation-change.h
@@ -35,10 +35,6 @@ class Truncation final {
   bool IsUsedAsFloat64() const {
     return LessGeneral(kind_, TruncationKind::kFloat64);
   }
-  bool IdentifiesMinusZeroAndZero() {
-    return LessGeneral(kind_, TruncationKind::kWord32) ||
-           LessGeneral(kind_, TruncationKind::kBool);
-  }
   bool IdentifiesNaNAndZero() {
     return LessGeneral(kind_, TruncationKind::kWord32) ||
            LessGeneral(kind_, TruncationKind::kBool);