Fix bug with range of shift operations.

runtime/vm/intermediate_language_mips.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_MIPS.
 #if defined(TARGET_ARCH_MIPS)
 
 #include "vm/intermediate_language.h"
 
 #include "vm/dart_entry.h"
@@ skipping 2620 matching lines @@
       __ sllv(result, left, TMP);
     }
     return;
   }
 
   const bool right_needs_check =
       (right_range == NULL) || !right_range->IsWithin(0, (Smi::kBits - 1));
   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());
         __ bltz(right, deopt);
       }
       Label done, is_not_zero;
 
       __ sltiu(CMPRES1,
           right, Immediate(reinterpret_cast<int32_t>(Smi::New(Smi::kBits))));
       __ movz(result, ZR, CMPRES1);  // result = right >= kBits ? 0 : result.
       __ sra(TMP, right, kSmiTagSize);
@@ skipping 2029 matching lines @@
   compiler->GenerateCall(token_pos(),
                          &label,
                          PcDescriptors::kOther,
                          locs());
   __ Drop(ArgumentCount());  // Discard arguments.
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_MIPS