RTS configure: Move over `eventfd`, `__thread`, and mem mgmt checks
All of this should boil down to AC_DEFINE
not AC_SUBST
, so it belongs in the RTS configure and should be safe to move without modification.
The RTS configure one has a new
AC_CHECK_SIZEOF([void *])
that the top-level configure version didn't have, so that ac_cv_sizeof_void_p
is defined. Once more code is moved over in latter commits, that can go away.
Progress towards #17191 (closed)
Edited by John Ericson