Is there a chance (workaround?) to compile "microcode" without removing the "configure" file and without recreating the PHP-configfile with "./buildconf"?

"./buildconf --force" runs into trouble, because outdated "autoconf" and outdated "libtool" on a machine I maintenance. So I tried to leave "configure" untouched and ran

  ./configure --with-microcode=shared --with-apxs=/usr/sbin/apxs
  make

in the PHP source-dir. But with this the default PHP binries are created, not the "microcode.so" (the "modules-dir" is empty).