Don't take UnkownOSRValues into account when infering Phi's representation.

src/type-info.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 350 matching lines @@
     BinaryOpIC::TypeInfo result_type = static_cast<BinaryOpIC::TypeInfo>(
         code->binary_op_result_type());
 
     switch (type) {
       case BinaryOpIC::UNINITIALIZED:
         // Uninitialized means never executed.
         return TypeInfo::Uninitialized();
       case BinaryOpIC::SMI:
         switch (result_type) {
           case BinaryOpIC::UNINITIALIZED:
+            if (expr->op() == Token::DIV) {
+              return TypeInfo::Double();
+            }
+            return TypeInfo::Smi();
           case BinaryOpIC::SMI:
             return TypeInfo::Smi();
           case BinaryOpIC::INT32:
             return TypeInfo::Integer32();
           case BinaryOpIC::HEAP_NUMBER:
             return TypeInfo::Double();
           default:
             return unknown;
         }
       case BinaryOpIC::INT32:
@@ skipping 301 matching lines @@
   USE(maybe_result);
 #ifdef DEBUG
   Object* result = NULL;
   // Dictionary has been allocated with sufficient size for all elements.
   ASSERT(maybe_result->ToObject(&result));
   ASSERT(*dictionary_ == result);
 #endif
 }
 
 } }  // namespace v8::internal