Bug12589870 post-merge fixes for Sparc64 and friends

sql/sp_head.cc:
  alignment-safe copy
sql/sql_cache.cc:
  alignment-safe copy
sql/sql_parse.cc:
  alignment-safe copy

sql/sp_head.cc

@@ -1044,7 +1044,7 @@ subst_spvars(THD *thd, sp_instr *instr, LEX_STRING *query_str)
   {
     memcpy(pbuf, qbuf.ptr(), qbuf.length());
     pbuf[qbuf.length()]= 0;
-    *(size_t *)(pbuf+qbuf.length()+1)= thd->db_length;
+    memcpy(pbuf+qbuf.length()+1, (char *) &thd->db_length, sizeof(size_t));
   }
   else
     DBUG_RETURN(TRUE);

sql/sql_cache.cc

@@ -1471,8 +1471,9 @@ Query_cache::send_result_to_client(THD *thd, char *sql, uint query_length)
       sure the new current database has a name with the same length
       as the previous one.
     */
-    size_t *db_len= (size_t *) (sql + query_length + 1);
-    if (thd->db_length != *db_len)
+    size_t db_len;
+    memcpy((char *) &db_len, (sql + query_length + 1), sizeof(size_t));
+    if (thd->db_length != db_len)
     {
       /*
         We should probably reallocate the buffer in this case,

sql/sql_parse.cc

@@ -492,6 +492,8 @@ static void handle_bootstrap_impl(THD *thd)
     query= (char *) thd->memdup_w_gap(buff, length + 1,
                                       thd->db_length + 1 +
                                       QUERY_CACHE_FLAGS_SIZE);
+    size_t db_len= 0;
+    memcpy(query + length + 1, (char *) &db_len, sizeof(size_t));
     thd->set_query(query, length);
     DBUG_PRINT("query",("%-.4096s", thd->query()));
 #if defined(ENABLED_PROFILING) && defined(COMMUNITY_SERVER)
@@ -1933,8 +1935,8 @@ bool alloc_query(THD *thd, const char *packet, uint packet_length)
     also store this length, in case current database is changed during
     execution.  We might need to reallocate the 'query' buffer
   */
-  size_t *len = (size_t *) (query + packet_length + 1);
-  *len= thd->db_length;
+  char *len_pos = (query + packet_length + 1);
+  memcpy(len_pos, (char *) &thd->db_length, sizeof(size_t));
     
   thd->set_query(query, packet_length);