[patch] fix build on architectures with a signed size_t

[Andrew Haley]

Florian Weimer wrote:
> * Florian Weimer:
> 
>> * Matthias Klose:
>>
>>> attached are three patches to build on architectures with a signed size_t
>>> (s390-linux-gnu).
>> Yuck.  Is this really true?  Seems so.
> 
> No, it's not.

It's not.

7.17 Common definitions <stddef.h>

1 The following types and macros are defined in the standard header
<stddef.h>. Some are also defined in other headers, as noted in their
respective subclauses.

2 The types are

  ptrdiff_t

which is the signed integer type of the result of subtracting two pointers;

  size_t

which is the unsigned integer type of the result of the sizeof operator;

Andrew.