No constant folding done for first arg of qp()

[ksvanhorn]

Expected Behaviour

It should be OK to have the following in a Chronikis program:

qp(24.0 * 7.0, 0.5, 10, rho_w, sigmap_w)

Actual Behaviour

I get the following error:

chronikisc: toModelBody requires an argument in BasicModel form
CallStack (from HasCallStack):
  error, called at src/InferShapesBoundsImpl.hs:205:17 in compiler-0.2.0.0-9V7qdTqRCYd5vzfi3sufpJ:InferShapesBoundsImpl

If I run with the -x flag, I find that the call to qp() doesn't get expanded.