Convert gdb_bfd.c to new hash table This converts the BFD cache in gdb_bfd.c to use the new hash table. Change-Id: Ib6257fe9d4f7f8ef793a2c82d53935a8d2c245a3 Co-Authored-By: Tom Tromey <tom@tromey.com> Approved-By: Tom Tromey <tom@tromey.com>