Segfaults when running bitwidth.b

[pythonmcpi]

I'm using the default settings and pypy (2.7) with this bitwidth.b program: link
gcc complains when I compile it (gcc bitwidth.c -O2 -o bitwidth.exe) and when I run the executable it segfaults.

gcc complaint:
bitwidth.c: In function ‘main’:
bitwidth.c:9:9: warning: large integer implicitly truncated to unsigned type [-Woverflow]
p[0] = 256;
^~~

[rdebath]

It's blowing on the "accesses before the start of the array" test.
This is a simpler trip for the same issue: https://github.com/rdebath/Brainfuck/blob/master/testing/Skiploop.b

With the most recent versions GCC or the linker have changed where static buffers are allocated; unmapped memory is now much closer.