Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Add hacks that I use to test cross-builds (by building on
native and foreign architectures and comparing products).
They eliminate most of the differences caused by different
object directory paths, timestamping, and identification.

(Note WORLDTMP was renamed to ${OBJTREE}${.CURDIR}/tmp.)