mozilla/rust — pull request #8072 by graydon (2013-07-27 03:28:46+00:00)
Title: Revert "De-share ast::Ty"

This reverts commit 47eca2113c5c55a4ffbb8c11a38c8ca7a79a1d72.

Rebased from @Aatch's previous PR #7644, attempting to land.