Update PPAPI IDL generator to define versioned structs, and unversioned typedef.

ppapi/thunk/ppb_directory_reader_thunk.cc

Index: ppapi/thunk/ppb_directory_reader_thunk.cc
diff --git a/ppapi/thunk/ppb_directory_reader_thunk.cc b/ppapi/thunk/ppb_directory_reader_thunk.cc
index f8e955370f4893af7f846774463b4ee217614258..4c57e5b1818271161654bf6eadb7167da2ef7b3e 100644
--- a/ppapi/thunk/ppb_directory_reader_thunk.cc
+++ b/ppapi/thunk/ppb_directory_reader_thunk.cc
@@ -46,7 +46,7 @@ const PPB_DirectoryReader_Dev g_ppb_directory_reader_thunk = {
 
 }  // namespace
 
-const PPB_DirectoryReader_Dev* GetPPB_DirectoryReader_Dev_Thunk() {
+const PPB_DirectoryReader_Dev_0_5* GetPPB_DirectoryReader_Dev_0_5_Thunk() {
   return &g_ppb_directory_reader_thunk;
 }