Revert "; * src/emacs.c (main): Improvements to last change."

This reverts commit c774e83e36.  It
causes crashes on GNU/Linux systems using libgmp, as there a shared
library initializer is used to set the malloc functions on startup, so
they are not dumped.

src/emacs.c

@@ -1937,9 +1937,7 @@ Using an Emacs configured with --with-x-toolkit=lucid does not have this problem
     }
 
   init_alloc ();
-#ifndef HAVE_UNEXEC
   init_bignum ();
-#endif
   init_threads ();
   init_eval ();
   running_asynch_code = 0;