[review v4] Add maint set/show worker-threads

[Eli Zaretskii]

> Date: Fri, 22 Nov 2019 18:50:07 -0500
> From: "Tom Tromey (Code Review)" <gerrit@gnutoolchain-gerrit.osci.io>
> Cc: Christian Biesinger <cbiesinger@google.com>
> 
> Change URL: https://gnutoolchain-gerrit.osci.io/r/c/binutils-gdb/+/174
> ......................................................................
> 
> Add maint set/show worker-threads
> 
> This adds maint commands to control the number of worker threads that
> gdb can use.
> 
> 2019-10-19  Tom Tromey  <tom@tromey.com>
> 
> 	* NEWS: Add entry.
> 	* maint.c (_initialize_maint_cmds): Add "worker-threads" maint
> 	commands.  Call update_thread_pool_size.
> 	(update_thread_pool_size, maintenance_set_worker_threads): New
> 	functions.
> 	(n_worker_threads): New global.
> 
> gdb/doc/ChangeLog
> 2019-10-19  Tom Tromey  <tom@tromey.com>
> 
> 	* gdb.texinfo (Maintenance Commands): Document new maint
> 	commands.

OK for the documentation parts.

Thanks.