that is another small step toward multilibs:
Changes:
* Eliminate RTEMS_CHECK_CUSTOM_BSP from all configure.ins below exec/
* Add RTEMS_CHECK_CUSTOM_BSP to the multilib-disabled branch in
RTEMS_ENV_RTEMSCPU to preserve the old per-BSP building scheme
functional.
Notes:
* --enable-multilibs is still non-functional
* This patch should not have any influence on the old building
scheme (--disable-multilib should silently fall back to the old
building scheme).
* running ./bootstrap is required after applying the patch
256cbecf68