Header guards (#744)
Header guards (#744)

* hard-coded header guard values

* Revert "hard-coded header guard values"

This reverts commit f666279f265139169ccf25a7aca25976e0f808f1.

* swap to shorter and more consistent #pragma once guard

* Clean up whitespace in compileProg' function

diku-dk/futhark,diku-dk/futhark,diku-dk/futhark,diku-dk/futhark,HIPERFIT/futhark,HIPERFIT/futhark,diku-dk/futhark,HIPERFIT/futhark