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

src/compiler/representation-change.h

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_COMPILER_REPRESENTATION_CHANGE_H_
 #define V8_COMPILER_REPRESENTATION_CHANGE_H_
 
 #include "src/compiler/js-graph.h"
 #include "src/compiler/simplified-operator.h"
 
@@ skipping 17 matching lines @@
   }
 
   // Queries.
   bool IsUnused() const { return kind_ == TruncationKind::kNone; }
   bool IsUsedAsWord32() const {
     return LessGeneral(kind_, TruncationKind::kWord32);
   }
   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);
   }
   bool IdentifiesUndefinedAndNaNAndZero() {
     return LessGeneral(kind_, TruncationKind::kFloat64) ||
            LessGeneral(kind_, TruncationKind::kWord64);
   }
 
   // Operators.
@@ skipping 228 matching lines @@
   Factory* factory() const { return isolate()->factory(); }
   SimplifiedOperatorBuilder* simplified() { return jsgraph()->simplified(); }
   MachineOperatorBuilder* machine() { return jsgraph()->machine(); }
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_REPRESENTATION_CHANGE_H_