I got a new Mac yesterday. I was looking for a package of GCC that included GDC but couldn't find one. So I made my own.
https://briancallahan.net/blog/20241212.html
Or if you just want the tarball: https://github.com/ibara/macOS-GDC/releases/download/14.2/gcc14.tgz
The tarball is designed to be extracted to / creating /opt/gcc
Don't know if anyone else is looking for this, but I was so here it is for everyone else.
~Brian