Re: seq#: do we actually need it as a primitive?

For posterity, the answer is no, and it is explained in this comment: https://ghc.haskell.org/trac/ghc/ticket/5129#comment:2 Edward Excerpts from David Feuer's message of 2015-01-07 11:12:55 -0800:

I've read about the inlining issues surrounding Control.Exception.evaluate that seem to have prompted the creation of seq#, but I'm still missing something. Isn't seq# a s the same as let !a' = a in (# s, a' #) ?

David