fsprojects/VisualFSharpPowerTools — pull request #866 by vasily-kirichenko (2014-11-17 13:58:16+00:00)
Title: Unused declarations optimization

* create a `Map>`, then use it to determine whether a symbol unused.

It decrease "slow" stage time (excluding `ParseAndCheckProject`) on `service.fs` from FCS solution from 58 seconds to 17 seconds.