malloc directly for storage, and abort if we don't get what we
want. The situation is much simpler --- just call malloc. Emacs
has bizarre/evil requirements (signal handlers might malloc unless
you set this global flag, so you have to set the flag around all
calls to malloc) which we are certainly not going to conform to,
so we can do the simple and obvious thing.
configure.in. Including this might cause problems if applications
that link against libguile include their own copies of alloca, but
if they're using autoconf, they should be adding libguile to LIBS
before calling AC_FUNC_ALLOCA anyway, in which case they'll find
the copy in libguile, and things will be okay. (I think.)
