THRIFT-3589 Pass references to field names in constructor through get_field_name

This closes #825
diff --git a/compiler/cpp/src/generate/t_dart_generator.cc b/compiler/cpp/src/generate/t_dart_generator.cc
index 0853a91..4faea19 100644
--- a/compiler/cpp/src/generate/t_dart_generator.cc
+++ b/compiler/cpp/src/generate/t_dart_generator.cc
@@ -830,7 +830,7 @@
     t_type* t = get_true_type((*m_iter)->get_type());
     if ((*m_iter)->get_value() != NULL) {
       print_const_value(out,
-                        "this." + (*m_iter)->get_name(),
+                        "this." + get_field_name((*m_iter)->get_name()),
                         t,
                         (*m_iter)->get_value(),
                         true,