EPA: Remove parenthesizeHsType

This is called from PostProcess.hs, and adds spurious parens.
With the looser version of exact printing we had before we could
tolerate this, as they would be swallowed by the original at the same
place.

But with the next change (remove EpAnnNotUsed) they result in
duplicates in the output.

For Darwin build:

Metric Increase:
    MultiLayerModulesTH_OneShot