Fix issue: 5427703 (compareTo), fix parsing of -0.0.

runtime/vm/ast.cc

 // Copyright (c) 2011, 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/ast.h"
 #include "vm/compiler.h"
 #include "vm/dart_entry.h"
 #include "vm/isolate.h"
 #include "vm/object_store.h"
 
@@ skipping 75 matching lines @@
       Smi& smi = Smi::Handle();
       smi ^= literal().raw();
       const Instance& literal =
           Instance::ZoneHandle(Integer::New(-smi.Value()));
       return new LiteralNode(this->token_index(), literal);
     }
     if (literal().IsDouble()) {
       Double& dbl = Double::Handle();
       dbl ^= literal().raw();
       // Preserve negative zero.
-      const Instance& literal =
-          Instance::ZoneHandle(Double::New(0.0 - dbl.value()));
+      double new_value = (dbl.value() == 0.0) ? -0.0 : (0.0 - dbl.value());
+      const Instance& literal = Instance::ZoneHandle(Double::New(new_value));
       return new LiteralNode(this->token_index(), literal);
     }
   }
   return NULL;
 }
 
 
 bool ComparisonNode::IsKindValid() const {
   return Token::IsRelationalOperator(kind_)
       || Token::IsEqualityOperator(kind_)
@@ skipping 337 matching lines @@
   if (field_value.IsUnhandledException()) {
     return NULL;
   }
   if (!field_value.IsNull()) {
     return &field_value;
   }
   return NULL;
 }
 
 }  // namespace dart