gptboot broken when compiled with clang 6 and WITHOUT_LOADER_GELI -- clang 5 is OK

[Dewayne Geraghty]

Andre, You're not alone.  I think there's a problem with clang6 on i386
FreeBSD 11.1X, refer:
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=227552
https://forums.freebsd.org/threads/uptime-w-i386-breakage.65584/
and perhaps also on amd64, search for
https://bugs.freebsd.org/bugzilla/buglist.cgi?quicksearch=clang&list_id=226390.

Without time to investigate I've reverted userland
FreeBSD 11.2-PRERELEASE  r332843M    amd64 1101515 1101509
FreeBSD 11.2-PRERELEASE  r332843M    i386 1101515 1101509

Apologies for my earlier email, I'd missed setting content-type:
text/plain instead of text/html (the latter strips content to the
mailing list), too many management memo's! ;)