[turbofan] Allow deoptimization for JSToNumber operator.

src/compiler/operator-properties.cc

 // 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.
 
 #include "src/compiler/operator-properties.h"
 
 #include "src/compiler/js-operator.h"
 #include "src/compiler/linkage.h"
 #include "src/compiler/opcodes.h"
 
@@ skipping 52 matching lines @@
     case IrOpcode::kJSMultiply:
     case IrOpcode::kJSShiftLeft:
     case IrOpcode::kJSShiftRight:
     case IrOpcode::kJSShiftRightLogical:
     case IrOpcode::kJSStoreNamed:
     case IrOpcode::kJSStoreProperty:
     case IrOpcode::kJSSubtract:
 
     // Conversions
     case IrOpcode::kJSToObject:
+    case IrOpcode::kJSToNumber:
 
     // Other
     case IrOpcode::kJSDeleteProperty:
       return true;
 
     default:
       return false;
   }
 }
 
@@ skipping 11 matching lines @@
   Operator::Opcode const opcode = op->opcode();
   return opcode == IrOpcode::kStart || opcode == IrOpcode::kEnd ||
          opcode == IrOpcode::kDead || opcode == IrOpcode::kLoop ||
          opcode == IrOpcode::kMerge || opcode == IrOpcode::kIfTrue ||
          opcode == IrOpcode::kIfFalse;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8