🚀 go-pugleaf

While porting the 5620 DMD software to a different architecture
(Gould PN6000), I discovered that whoever wrote some of the
"ld" source code took advantage of knowledge of how malloc()
operates in order to perform extra validity checking in the
myfree() routine.  Unfortunately, he did not do this correctly.
The "nextblk" pointer is stored in a (union store) before the
malloc return value, not in a (char **).  These need not be the
same size, and on the Gould they weren't.

Either the necessary code from malloc() should be borrowed, or
(much better) the extra validity checking should be removed or
done in some system-independent way.

The source file I found this in was
	$DMDSGS/sgs/mac/common/ofc/ld/util.c
Presumably the analogous file in the "ld" sources in other AT&T
SGS packages has the same problem.