google/dagger — pull request #14 by cgruber (2013-11-19 22:10:12+00:00)
Title: Integrate performance fix for plus with open-source head.

The commits are amusingly independent (nearly clean merges) but a few changes in head negate the net-effect in our internal fix. This reverts one of those commits, and slightly adapts the code at HEAD to properly handle SetBindings and .plus() without killing the performance gain.