Update project authors statements to Dartino

src/vm/assembler_x64_macos.cc

-// Copyright (c) 2015, the Fletch project authors. Please see the AUTHORS file
+// Copyright (c) 2015, the Dartino 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.md file.
 
 #if defined(FLETCH_TARGET_X64) && defined(FLETCH_TARGET_OS_MACOS)
 
 #include <stdio.h>
 #include "src/vm/assembler.h"
 
 namespace fletch {
 
@@ skipping 48 matching lines @@
   Print("movq (%rq,%rq,8), %rq", destination, index, destination);
 }
 
 void Assembler::LoadLabel(Register reg, const char* name) {
   Print("leaq _%s(%%rip), %rq", name, reg);
 }
 
 }  // namespace fletch
 
 #endif  // defined(FLETCH_TARGET_X64) && defined(FLETCH_TARGET_OS_MACOS)