Fixed a small error in the IF1 reference
Compiled away semantics differences between IF1 and DIS

- Added some extra natives
- Operations that are commented out in the IF1 frontend operations file
  are not likely to be added in the future.
- Added conversions for: ABuild, AFill, AGather, AScatter, ALimL, ASetL, Call, Less, LessEq
- Added functions to add multiple targets and to remove targets to IGR ports