A follow up patch for the follow up patch for Bug#45829

"CREATE TABLE TRANSACTIONAL PAGE_CHECKSUM ROW_FORMAT=PAGE accepted, 
does nothing".

Put back stubs for members of structures that are shared between
sql/ and pluggable storage engines. to not break ABI unnecessarily.
To be NULL-merged into 5.4, where we do break the ABI already.

sql/handler.h

@@ -895,6 +895,8 @@ class partition_info;
 struct st_partition_iter;
 #define NOT_A_PARTITION_ID ((uint32)-1)
 
+enum enum_ha_unused { HA_CHOICE_UNDEF, HA_CHOICE_NO, HA_CHOICE_YES };
+
 typedef struct st_ha_create_information
 {
   CHARSET_INFO *table_charset, *default_table_charset;
@@ -916,10 +918,12 @@ typedef struct st_ha_create_information
   uint options;				/* OR of HA_CREATE_ options */
   uint merge_insert_method;
   uint extra_size;                      /* length of extra data segment */
+  enum enum_ha_unused unused1;
   bool table_existed;			/* 1 in create if table existed */
   bool frm_only;                        /* 1 if no ha_create_table() */
   bool varchar;                         /* 1 if table has a VARCHAR */
   enum ha_storage_media storage_media;  /* DEFAULT, DISK or MEMORY */
+  enum enum_ha_unused unused2;
 } HA_CREATE_INFO;
 
 

sql/table.h

@@ -361,6 +361,8 @@ typedef struct st_table_share
   }
   enum row_type row_type;		/* How rows are stored */
   enum tmp_table_type tmp_table;
+  enum enum_ha_unused unused1;
+  enum enum_ha_unused unused2;
 
   uint ref_count;                       /* How many TABLE objects uses this */
   uint open_count;			/* Number of tables in open list */