Remove GENERATED pragma
@alanz pointed out on
ghc-devs that the payload of this pragma does not appear to be used anywhere. I did some digging and traced the pragma's addition back to
d386e0d2 (way back in 2006!). It appears
that it was intended to be used by code generators for use in informing
the code coveraging checker about generated code provenance. When it was
added it used the pragma's "payload" fields as source location
information to build an "ExternalBox". However, it looks like this
was dropped a year later in 55a5d8d9 .
At this point it seems like the pragma serves no useful purpose. Given that it also is not documented, I think we should remove it.