Obscure crashes due to gcc 4.9 -O2 => -fisolate-erroneous-paths-dereference

[Chris Johns]

On 19/02/2015 7:25 am, Joel Sherrill wrote:
>
> Yep. But if all we have is writeable vector tables at 0x0, then it MIGHT be
> ok. GCC may not be able to detect.  But on the m68k's without a VBR
> register the table is always at 0x0.

Yeap ...

https://git.rtems.org/rtems/commit/?id=dd309b10544bfceda968ac847ad34c3d90ca8281

I hit this one when testing on the mc5235.

Chris