Bug#16317363: Re-execute procedure, crash in mark_select_range_as_dependent

This problem here is that we reach ::fix_outer_field when we should not,
which happens because cached_table->select_lex of an Item_field no longer
matches the select_lex of the name resolution context. It is also important
to notice that this happens for a merged view, regular table fields are
not affected.

The mismatch is caused by 2 problems:

1. is a lacking update of TABLE_LIST::select_lex in
   convert_subquery_to_semijoin(). This code:

    for (TABLE_LIST *emb= tl->embedding;
         emb && emb->select_lex == old_sl;
         emb= emb->embedding)
      emb->select_lex= parent_join->select_lex;

   updates the select_lex of all leaf tables and embedding join nests,
   however it is necessary that all join nests have a correct select_lex
   pointer for this to work, so the fix is to add an assignment to
   ::select_lex in st_select_lex::nest_last_join().

2. is a lacking update of TABLE_LIST::select_lex when a view is merged
   into a query. It is solved quite elegantly by replacing the pointer
   in repoint_contexts_of_join_nests().

We have also taken the opportunity to replace the static function
alloc_join_nest() with a more general function TABLE_LIST::new_join_nest(),
which assigns values to all important join nest fields.

sql/sql_optimizer.cc
  In convert_subquery_to_semijoin(), remember to set select_lex
  pointer when creating new join nests.
  Function alloc_join_nest() is replaced with TABLE_LIST::new_join_nest().

sql/sql_parse.cc
  In st_select_lex::nest_last_join(), set select_lex pointer.

sql/sql_view.cc
  In repoint_contexts_of_join_nests(), update select_lex pointer of
  embedded join nests to point to the select_lex of the outer query.

sql/table.cc
  Added function TABLE_LIST::new_join_nest().

sql/table.h
  Added function TABLE_LIST::new_join_nest().