Main fix was to not cache derivied tables as they may be temporary tables that are deleted before the next query.
This was a bit tricky as Item_field::fix_fields depended on cached_tables to be set to resolve some columns.



mysql-test/r/sp-bugs.result:
  Added test case
mysql-test/t/sp-bugs.test:
  Added test case
sql/item.cc:
  Fixed fix_outer_field to handle case where found field did not have in cached_table
  Idea is that if cached_table is not avaliable, use from_field->table->pos_in_table_list instead
sql/records.cc:
  Also accept INTERNAL_TMP_TABLE for memmap
sql/sql_base.cc:
  More DBUG_PRINT
  Fixed that setup_natural_join_row_types() is not run twice.
  Original code modified context->first_name_resolution_table also for second executions.
  This was wrong as this could give wrong results if some joins had been optimized away between calls.
sql/sql_derived.cc:
  Mark derived tables as internal temporary tables (INTERNAL_TMP_TABLE), not as NON_TRANSACTIONAL_TMP_TABLE.
  This is more correct as the tables are not visible by the end user.
sql/sql_insert.cc:
  Reset pos_in_table_list before calling fix_fields.
  One of the consequences of the change of not caching all generated tables in Item_ident is that
  pos_in_table_list needs to be correct in calls to fix_fields.
sql/sql_lex.cc:
  More DBUG_PRINT
sql/sql_parse.cc:
  Don't cache derivied tables as they may be temporary tables that are deleted before the next query
sql/sql_select.cc:
  Reset table_vector. This was required as some code checked the vector to see if temporary tables had already been created.
sql/table.cc:
  Mark tables with field translations as cacheable (as these will not disapper between stmt executions.