[PATCH] [BasicAA] Make better use of zext and sign information.

[Nick White]

You're right - that call doesn't actually affect anything so I've removed it. It seems the actual cause of Rich's bug was using AllPositive to break out of the loop; if the loop break condition `i != e` is changed to `i != e && AllPositive` then the //test_modulo_analysis_with_global// test I've added will fail as the `Modulo` will be calculated incorrectly (as the last loop iteration is skipped, so `Modulo` isn't updated with its `Scale`). I've also added a few more tests and comments for the modulo functionality too, as I spent a bit of time exploring how it works. Thanks -

http://reviews.llvm.org/D5866