Massive PORTREVSION bump for gcc8

[Kevin Oberman]

This morning the PORTREVISION on at least hundreds of ports was bumped
because gcc8 was declared as the "canonical" version. As a result, I will
have about 300 ports to rebuild which will take many hours.
Why?

If a port is built and running properly with gcc7, I see no reason to force
the rebuild of all of the ports that are built with gcc7. This will lead to
a delay of probably several days in getting updated packages built for
LATEST repos and will consume hours of CPU time for everyone using
poudriere or building from ports. This even impacts (slightly) climate
change with the extra energy used in rebuilding all of those ports across
the globe.

Perhaps there was a real reason this was required. I have certainly never
seen it before for any new compiler version to either gcc or llvm.
--
Kevin Oberman, Part time kid herder and retired Network Engineer
E-mail: rkoberman at gmail.com
PGP Fingerprint: D03FB98AFA78E3B78C1694B318AB39EF1B055683