cannot specify PTL_SIZE_MAX for ptl_ni_limits_t about portals4 HOT 2 CLOSED

> Since the requested value is passed as an unsigned 64bit type (ptl_size_t) it
> is truncated to 0 when automatically cast to a long.

Portals4 reference implementation only supports 64-bit platforms currently.
So, sizeof(ptl_size_t) == sizeof(long) unless I am misunderstanding something.

Thus the problem is not truncation, but rather that when taken as a signed type 
PTL_SIZE_MAX "looks like" -1.  That triggers this logic in chk_param just as 0 
would:
        if (val < p->min)
                return p->min;
and thus you see the minimum values as reported.

I would speculate that changing the type of the 'val' argument of chk_param() 
to "unsigned long" or "uint64_t" should fix the problem.  However, I don't know 
enough to predict if that would break something else (e.g. are any parameter 
values ever legally negative?)

Fixed as of r2210