Fix bug with range of shift operations.

runtime/vm/intermediate_language_x64.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"  // Needed here to get TARGET_ARCH_X64.
 #if defined(TARGET_ARCH_X64)
 
 #include "vm/intermediate_language.h"
 
 #include "vm/dart_entry.h"
@@ skipping 2637 matching lines @@
     }
     return;
   }
 
   const bool right_needs_check =
       (right_range == NULL) || !right_range->IsWithin(0, (Smi::kBits - 1));
   ASSERT(right == RCX);  // Count must be in RCX
   if (is_truncating) {
     if (right_needs_check) {
       const bool right_may_be_negative =
-          (right_range == NULL) || right_range->IsNegative();
+          (right_range == NULL) || !right_range->IsPositive();
       if (right_may_be_negative) {
         ASSERT(shift_left->CanDeoptimize());
         __ CompareImmediate(right, Immediate(0), PP);
         __ j(NEGATIVE, deopt);
       }
       Label done, is_not_zero;
       __ CompareImmediate(right,
           Immediate(reinterpret_cast<int64_t>(Smi::New(Smi::kBits))), PP);
       __ j(BELOW, &is_not_zero, Assembler::kNearJump);
       __ xorq(left, left);
@@ skipping 3154 matching lines @@
                          PcDescriptors::kOther,
                          locs());
   __ Drop(ArgumentCount());  // Discard arguments.
 }
 
 }  // namespace dart
 
 #undef __
 
 #endif  // defined TARGET_ARCH_X64