[PATCH v2] Add support/ code for checking file contents

[Florian Weimer]

* Joseph Myers:

> I've updated various comments as indicated.  I'm wary of reporting read 
> errors via process termination at this level of nesting (they wouldn't say 
> anything much useful about which subtest was executing at the time of the 
> error, unless the interfaces are changed to pass in __FILE__ and __LINE__ 
> - an advantage of detecting them the same as comparison failures, in the 
> caller, is that this means better diagnostics).

Good point, makes sense.

> I did make the code treat a read error when EOF is expected the same as a 
> comparison failure.
>
>
>
> Add support/ code for checking file contents
>
> For use in freopen tests, add various support/ helper interfaces for
> use in checking file contents.
>
> Tested for x86_64.

This version looks good to me, thanks.

Reviewed-by: Florian Weimer <fweimer@redhat.com>

Florian