[RFTesters] Make portable sgetn/1-in and 1-io tests

[Andreas Tobler]

Paolo Carlini wrote:

> Hi everyone,
> 
> perhaps I have nailed down the reason underlying the
> failure on *many* platforms of 27_io/basic_filebuf/sgetn/char/1-in.cc
> and 1-io.cc: seems due to the value of BUFSIZ not being
> 8192 everywhere.
> 
> If my hypothesis is correct the below should fix it.
> 
> Many thanks in advance,


Hm, on a first view it seems darwin likes it :)

PASS: 27_io/basic_filebuf/sgetn/char/1-in.cc (test for excess errors)
PASS: 27_io/basic_filebuf/sgetn/char/1-in.cc execution test

PASS: 27_io/basic_filebuf/sgetn/char/1-io.cc (test for excess errors)
PASS: 27_io/basic_filebuf/sgetn/char/1-io.cc execution test

Andreas