mozilla/rust — pull request #12206 by sfackler (2014-02-12 06:48:39+00:00)
Title: Stop unloading syntax libraries

Externally loaded libraries are able to do things that cause references
to them to survive past the expansion phase (e.g. creating @-box cycles,
launching a task or storing something in task local data). As such, the
library has to stay loaded for the lifetime of the process.

r? @pcwalton @alexcrichton