[PATCH] Scoped NoAlias Metadata

[Chandler Carruth]

  Hal rebased this and that got it into my inbox again.

  I'll look at the code soon, but I had a high-level comment: this is solving an extremely similar problem to lifetime markers. I would be interested to see to what degree the two should or should not share the same design principles, and why. Maybe Nick should comment on this in general?

http://llvm-reviews.chandlerc.com/D2194