Fix bug with range of shift operations.

runtime/vm/intermediate_language_arm64.cc

 // Copyright (c) 2014, 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_ARM64.
 #if defined(TARGET_ARCH_ARM64)
 
 #include "vm/intermediate_language.h"
 
 #include "vm/dart_entry.h"
@@ skipping 2562 matching lines @@
       EmitJavascriptOverflowCheck(compiler, shift_left->range(), deopt, result);
     }
     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());
         __ CompareRegisters(right, ZR);
         __ b(deopt, MI);
       }
 
       __ CompareImmediate(
           right, reinterpret_cast<int64_t>(Smi::New(Smi::kBits)), PP);
       __ csel(result, ZR, result, CS);
       __ SmiUntag(TMP, right);
@@ skipping 2734 matching lines @@
   compiler->GenerateCall(token_pos(),
                          &label,
                          PcDescriptors::kOther,
                          locs());
   __ Drop(ArgumentCount());  // Discard arguments.
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM64