fix build with GCC-based architectures.

prior to this patch, some archs still using GCC could not compile the port;
tested on powerpc64 (sponsored hardware);
also tested on other archs to check if nothing broke.

• original patch modified just to bump PORTREVISION, and use PORTSDIR root.

PR: 232276
Submitted by: Piotr Kubaj <pkubaj@anongoth.pl>
Approved by: rene (mentor)
Sponsored by: IntegriCloud