If NO_ARCH is set then check that no FreeBSD elf(5) files are in $STAGEDIR.
If an elf(5) file is bundles as part of the package, but is not meant to be
run directly (i.e. the elf(5) file is a payload, and not compiled) then
those files can be added to NO_ARCH_IGNORE to avoid the check from failing,

Changes to ports:
 - Ports that have NO_ARCH set, but actually compile files have had NO_ARCH
   removed.
 - Ports that have elf(5) payloads have had those files added to
   NO_ARCH_IGNORE.
 - R-cran ports that do not set USES=cran:compiles have NO_ARCH set,

PR:		218976
Reviewed by:	antoine, mat
Approved by:	portmgr