Make generate_program virtual.

Haskell and OCaml need to override this to put typedefs at the end.


git-svn-id: https://svn.apache.org/repos/asf/incubator/thrift/trunk@665590 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/compiler/cpp/src/generate/t_generator.h b/compiler/cpp/src/generate/t_generator.h
index 594bed9..8636314 100644
--- a/compiler/cpp/src/generate/t_generator.h
+++ b/compiler/cpp/src/generate/t_generator.h
@@ -34,9 +34,9 @@
   /**
    * Framework generator method that iterates over all the parts of a program
    * and performs general actions. This is implemented by the base class and
-   * should not be overwritten in the subclasses.
+   * should not normally be overwritten in the subclasses.
    */
-  void generate_program();
+  virtual void generate_program();
 
   const t_program* get_program() const { return program_; }