compiler: don't localize names in export data

    
    Localizing names in export data causes the compiler output to change
    depending on the LANG environment variable, so don't do it.
    
    Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/214038

From-SVN: r280057

gcc/go/gofrontend/MERGE

-8ad32fb3e1e8b19ac125d03db24a73a800abdfa6
+f9d1bfb3eec2d388c5f239779fd25a580064dd9d
 
 The first line of this file holds the git revision number of the last
 merge done from the gofrontend repository.

gcc/go/gofrontend/export.cc

@@ -1231,7 +1231,7 @@ Export::write_name(const std::string& name)
   if (name.empty())
     this->write_c_string("?");
   else
-    this->write_string(Gogo::message_name(name));
+    this->write_string(Gogo::unpack_hidden_name(name));
 }
 
 // Write an integer value to the export stream.