perl 3.0 dumps core

[Guy Harris]

>Did I answer something incorrectly in the configure script?

Probably not.

The problem appears to be due to the use of "vfork" in "mypopen" in
"util.c"; fixes to that and other problems (including previously-posted
"diff"s) are in another posting following this.

(As for why this is, we quote from the SunOS 4.0 <vfork.h>:

/*
 * this atrocity is necessary on sparc because registers modified
 * by the child get propagated back to the parent via the window
 * save/restore mechanism.
 */

Now, if there weren't programs out there that relied, either explicitly
or implicitly, on the behavior of the BSD "vfork" implementation (e.g.,
C shell depending on the fact that it blocks the parent in order to let
it set up the process groups correctly - Chris Torek recently mentioned
what the right way to do that is in "comp.unix.wizards", I think - or
programs depending on the memory-sharing semantics that the manual page
went to great pains to tell you was NOT guaranteed to be there in the
future), "vfork" in 4.0 could just have been the same as "fork" as we
could have avoided all this pain.  But nooooo....)