- Remove free Swift functions for advance and distance and replace
them with protocol extension methods:
- advancedBy(n)
- advancedBy(n, limit:)
- distanceTo(end)
- Modernize the Index tests
- Use StdlibUnittest
- Test for custom implementation dispatch
Perf impact: No significant changes reported in the
Swift Performance Measurement Tool.
rdar://problem/22085119
Swift SVN r30958
This decreases total testing time by over a minute on my old Mac Pro.
It probably has much less effect on systems with fewer cores, but shouldn't
be any worse there.
Swift SVN r22745