To call the constructor we now only store the CE and a HashTable for the arguments.
This reduces the size of the _pdo_stmt_t struct from 320 bytes to 232 bytes.
Moreover, this now means that the constructor argument array follows the usual CUFA semantics.
This change is a BC break, as string keys now act like named arguments.
Moreover, the automatic wrapping of by-value arguments for by-ref parameters has been dropped, and the usual E_WARNING is now emitted in those cases.
The do_fetch() is heavily refactored to simplify the execution flow, which also makes it easier to understand.
Additionally we add a new bitflag in_fetch to prevent modification of the fetch flags by userland when PDO is fetching from the DB.
Gina Peter Banyard
3ff7758bcf