[PATCH] build: Update configure.ac to support the latest automake.

[Chris Johns]

On 1/4/18 1:58 pm, Joel Sherrill wrote:
> Great job! 

Thanks. Simpler than I expected.

> 
> What needs to be done to give any more confidence? 
> 

Some testing. The change was simple so I do not expect too many issues.

> When do we upgrade automake in the RSB? 
> 

Patch posted.

> And fwiw I would like to see the last three POSIX .h files moved to newlib. The
> next newlib bump already will fix a couple of pthread prototypes.

OK.

Chris

ps: You should be having a log weekend off!