[PATCH] Add a testcase for PR binutils/23460

[Nick Clifton]

Hi H.J.

> Add a testcase to limit open files to 16 for AR with plugin.  Before
> 
> commit 103da91bc083f94769e3758175a96d06cef1f8fe
> Author: Nick Clifton <nickc@redhat.com>
> Date:   Wed Aug 1 14:34:41 2018 +0100
> 
>     Close resource leaks in the BFD library's plugin handler.
> 
> it failed with:
> 
> ../binutils/ar: tmpdir/pr23460f.o: plugin needed to handle lto object
> 
> OK for master branch?

Approved - please apply - and thanks very much for doing this.

Cheers
  Nick