Crash during try to load STEP file with a sample C31 on NT.

A problem is got from our customer, it is a STEP file
which doesn't pass, on NT, version OCC 3.1

This file is SUPPORT-MIROIR.stp.

I reproduced the crash with a sample C31 on NT.
But it passes well with DRAW on SUN (C31 and C40).
Result brep from C40 (compressed) is a the
SUPPORT-MIROIR.brep.
It looks fine (checkshape OK, tolerance 0.0003...) .
But there are free bounds in C31 while there is none
in C40 (there should not be because it is describd
a SOLID). And the result from C31 has 162 faces only
(163 in C40, as in the STEP file). I don't know if it
is the same reason.

For fixes, the version OCC31 already sent to the customer
is to consider as basis.

It's possible that some fixes done for ATS version already
(managed by PDN) can address this particular problem, who
knows ?