2002-09-21 Robert Collins <rbtcollins@hotmail.com>

2002-09-21  Robert Collins <rbtcollins@hotmail.com>

        * thread.cc: Partial refactoring of pthread_key destructor
        handling. Loosely based on Thomas Pfaff's work.
        (pthread_key_destructor_list::Insert): Remove.
        (pthread_key_destructor_list::Pop): Remove.
        (pthread_key_destructor_list::IterateNull): Call the key's
        run_destructor method.
        (pthread_key::pthread_key): Initialize new member.
        (pthread_key::get): Mark as const for correctness.
        (pthread_key::run_destructor): Implement.
        * thread.h (pthread_key::get): Mark as const for correctness.
        (pthread_key::run_destructor): Declare.
        (List): New template class that implements a generic list.
        (pthread_key_destructor_list): Inherit from List, and remove
        now duplicate functions.