lang/gcc6-aux: update to GCC-6.5.0, regen bootstraps (+)

Original MASTERSITE is dead now and bootstraps is not available anymore.

Update GCC components from 6.4.1 to 6.5.0, latest 6.x release.
Regen all ada boostraps to 6.5.0 release, made all for minimal supportted FreeBSD release, 13.5.
Point WWW to original jmarino's ada development environment, https://github.com/jrmarino/draco

PR: 292414
MFH: 2026Q1
(cherry picked from commit 0286baf75e6a15721015ae1b4838bcbd6afdc218)