Project:Toolchain/sys-libs/glibc

WIP.

Checklist

 * Test 's scanelf, especially within Portage.
 * Every (almost?) release of glibc requires updating of the seccomp syscall whitelist within pax-utils.
 * It must be refreshed and the dependency within the new glibc ebuilds (and 9999) must be updated to reflect this, or corruption may occur within the VDB.
 * Do not keyword glibc until you are very confident that pax-utils is fine.