Gcc is a huge package and takes a very long time to compile. Allow the build process to skip bootstrapping http://gcc.gnu.org/install/build.html, see "--disable-bootstrap" Reproducible: Always
Optional behavior suggestion, of course. Perhaps with a "no-bootstrap" use flag of some sort.
you can already do this in per-package env. this isn't USE flag worthy. EXTRA_ECONF='--disable-bootstrap' so if that's all you need, i guess there's no work necessary here.