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
Add test033/run, test034/run to cabal file
Merge pull request #627 from markuspf/llvm-float-prim2

Add floating point primitives to LLVM backend