- strip package.use.force (i.e. building x86_64 on x86_64 gets forced multilib)
- filter /usr/CTARGET/ from revdep-rebuild #182601

- HOST_ABI and TARGET_ABI selection; consider:
	- build a 64bit (amd64) cross-compiler which targets 32bit (x86)
	- build a 64bit (amd64) cross-compiler which targets x32
	- ABI variables atm do not differentiate between host

- package.use not getting setup correctly:
# cat /etc/portage/package.use/cross-x86_64-cros-linux-gnu
cross-x86_64-cros-linux-gnu/gdb sys-devel gdb
cross-x86_64-cros-linux-gnu/insight dev-util insight
cross-x86_64-cros-linux-gnu/binutils -selinux multilib