A recent commit removed DIAGNOSTIC_IGNORE_UNUSED_FUNCTION, which was
used in thread-pool.c. This patch changes this code to use
ATTRIBUTE_UNUSED instead.
Tested by rebuilding.
gdb/ChangeLog
2019-12-12 Tom Tromey <tromey@adacore.com>
* gdbsupport/thread-pool.c (set_thread_name): Use
ATTRIBUTE_UNUSED.
Change-Id: I56d46eaac73690565d0e52db1791411567a918dd