[PATCH] Teach ScalarEvolution to use !range metadata.

[Sanjoy Das]

>>! In D5638#9, @hfinkel wrote:
> Also, looking at this patch made me think: We don't handle range metadata in LazyValueInfo, do we? And we don't seem to, and I think your GetRangeFromMetadata will be useful for both cases.

The only other use I could find was in ValueTracking.cpp where the range metadata is used to compute "known bits".  This information could be indirectly flowing in into LazyValueInfo, but I could not find any direct reference.  I haven't look very hard either. :)

>  You might consider making it a general utility function somewhere.

What is a good place for that?

http://reviews.llvm.org/D5638