[arm64] Fix order of decoder visitor add functions

AppendVisitor and PrependVisitor implementations were switched.

BUG=
R=ulan@chromium.org

Review URL: https://codereview.chromium.org/519723002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@23526 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/arm64/decoder-arm64.cc

@@ -17,13 +17,13 @@ namespace internal {
 
 void DispatchingDecoderVisitor::AppendVisitor(DecoderVisitor* new_visitor) {
   visitors_.remove(new_visitor);
-  visitors_.push_front(new_visitor);
+  visitors_.push_back(new_visitor);
 }
 
 
 void DispatchingDecoderVisitor::PrependVisitor(DecoderVisitor* new_visitor) {
   visitors_.remove(new_visitor);
-  visitors_.push_back(new_visitor);
+  visitors_.push_front(new_visitor);
 }