scala/scala — pull request #3447 by retronym (2014-01-31 21:10:44+00:00)
Title: Optimize the pickler phase

- move "erroneous type" diagnostic into a crash recovery handler,
rather than running it proactively
- move the "unexpanded macros" check into refchecks.

Cuts this phase in half, from about 1% of compile time to 0.5%.

Review by @adriaanm