When signalling an error we try to allocate an object. If that fails (presumably
because we are out of space) we print a message **TOTALLY OUT OF MEMORY**.
That is misleading because we are not totally out of memory, just out of heap.
The user has the option of restarting with a bigger heap and trying again.

[Addendum] There is a related misleading message in gc.c, where we say we are
out of memory when we are just out of heap. The equivalent fix is indicated.