track index bounds in ivory Proc types
comments after return aren't dead code
Merge remote-tracking branch 'refs/remotes/upstream/master' into index-type

Conflicts:
	ivory-opts/src/Ivory/Opts/ConstFold.hs
Merge remote-tracking branch 'upstream/master' into index-type
Merge pull request #14 from gridaphobe/index-type

Track index bounds in the types of Ivory procs