haskell: re-enable profiling on aarch64
The main problem was GHC exceeding the Hydra output limit with profiling
libs on aarch64-linux which made us disable the feature. Nowadays the
limit is 3GB, the GHC output is a bit over 2GB, so easily under the
limit.
aarch64-darwin uses a different codegen backend and was never really
affected by the problem: Its output with profiling enabled is around
1.6GB.
Consequently we can enable profiling for all platforms again, as we have
no output size issues for those we build on Hydra.
Thanks to flokli for helping me track down these up to date numbers.