Report functions that allocate fusible constructors or make function calls

[harendra-kumar]

We can have an option to report functions that are marked with FUSED and allocate any constructors rather than reporting only constructors that have been marked with FUSE. This way we can figure out if any constructors need to be marked with FUSE.

Also to aid foldr/build fusion we can also mark foldr/build fused function with the FUSED pragma, and report if functions that are marked FUSED are being called by someone.