Add `fxsave` area and a boundary word to catch bugs.  Should refactor rep.
Merge branch 'fsk-local-to-eris' into fsk-pnkgc-play

Conflicts:
	src/libstd/rt/context.rs
Merge branch 'fsk-pnkgc-play' of github.com:pnkfelix/rust into fsk-pnkgc-play