Add floating point primitives to LLVM backend

* implement floating point primitives in LLVM codegen
* add a test for the presence of floating point primitives
  in a given backend
Make runtest.pl execute run scripts directly
Add tests test033 and test034 to cabal file
There are no .idr files in test034
Re-enable calling terminate(vm) for its side effects
(was commented out in dce3569681698ca70edfa306e39dc94a1b1c1025)
Add test033/run, test034/run to cabal file
Move floating point operations out of Prelude
Add lib/Data/Floats.idr
Merge pull request #627 from markuspf/llvm-float-prim2

Add floating point primitives to LLVM backend
Merge pull request #643 from hannesm/runtime-side-effects

Re-enable calling terminate(vm) for its side effects
Remove Prelude/Complex.idr from base.ipkg
Merge pull request #648 from markuspf/float-prelude

Float prelude