Add a patch that we pulled into gcc6-devel via upstream a few days ago
that addresses a real-world issue around threading and unwinding as
files/patch-freebsd-unwind.h .

This will become obsolete with the next release of GCC 6, GCC 6.5.

Bump PORTREVISION since this is a functional change.

On the way fix up the format for files/patch-armv7-support . [1]

Reported by: portlint [1]