[crankshaft] Fix constant folding of HDiv instruction.

src/crankshaft/hydrogen-instructions.cc

 // Copyright 2012 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/crankshaft/hydrogen-instructions.h"
 
 #include "src/base/bits.h"
 #include "src/base/ieee754.h"
 #include "src/base/safe_math.h"
 #include "src/crankshaft/hydrogen-infer-representation.h"
@@ skipping 3560 matching lines @@
   if (FLAG_fold_constants && left->IsConstant() && right->IsConstant()) {
     HConstant* c_left = HConstant::cast(left);
     HConstant* c_right = HConstant::cast(right);
     if ((c_left->HasNumberValue() && c_right->HasNumberValue())) {
       if (c_right->DoubleValue() != 0) {
         double double_res = c_left->DoubleValue() / c_right->DoubleValue();
         if (IsInt32Double(double_res)) {
           return H_CONSTANT_INT(double_res);
         }
         return H_CONSTANT_DOUBLE(double_res);
-      } else {
+      } else if (c_left->DoubleValue() != 0) {
         int sign = Double(c_left->DoubleValue()).Sign() *
                    Double(c_right->DoubleValue()).Sign();  // Right could be -0.
         return H_CONSTANT_DOUBLE(sign * V8_INFINITY);
+      } else {
+        return H_CONSTANT_DOUBLE(std::numeric_limits<double>::quiet_NaN());
       }
     }
   }
   return new (zone) HDiv(context, left, right);
 }
 
 HInstruction* HBitwise::New(Isolate* isolate, Zone* zone, HValue* context,
                             Token::Value op, HValue* left, HValue* right) {
   if (FLAG_fold_constants && left->IsConstant() && right->IsConstant()) {
     HConstant* c_left = HConstant::cast(left);
@@ skipping 435 matching lines @@
     case HObjectAccess::kExternalMemory:
       os << "[external-memory]";
       break;
   }
 
   return os << "@" << access.offset();
 }
 
 }  // namespace internal
 }  // namespace v8