Re: new heapcheck contrib module

I wrote:
> I get
> off = 7777, flags = 2, len = 3bbb
> on a little-endian machine, and
> off = 3bbb, flags = 2, len = 7777
> on big-endian.  It'd be less symmetric if the bytes weren't
> all the same ...

... but given that this is the test value we are using, why
don't both endiannesses whine about a non-maxalign'd offset?
The code really shouldn't even be trying to follow these
redirects, because we risk SIGBUS on picky architectures.

            regards, tom lane