When a view statement is compiled on CREATE VIEW time, most of the 
optimizations should not be done. Finding the right optimization 
for a subquery is one of them.
Unfortunately the optimizer is resolving the column references of 
the left expression of IN subqueries in the process of deciding 
witch optimization to use (if needed). So there should be a 
special case in Item_in_subselect::fix_fields() : check the 
validity of the left expression of IN subqueries in CREATE VIEW 
mode and then proceed as normal. 


mysql-test/r/subselect.result:
  test case
mysql-test/r/view.result:
  chnaged explain due to column being resolved
mysql-test/t/subselect.test:
  test case
sql/item_subselect.cc:
  overloaded fix_fields to fix the left_expr in prepare_view_mode
sql/item_subselect.h:
  fix_fields overloaded so it can prepare left_expr