rust-lang/rust — pull request #17647 by pcwalton (2014-09-30 04:54:48+00:00)
Title: librustc: Stop looking in metadata in type contents.

4x improvement in pre-trans compile time for rustc.

I don't know exactly what made this regress so badly…maybe it was all the lifetimes that @eddyb landed. Regardless this is an enormous improvement in compile times.

r? @brson