[GHC] #14375: Implement with# primop

[GHC]

#14375: Implement with# primop
-------------------------------------+-------------------------------------
        Reporter:  simonpj           |                Owner:  bgamari
            Type:  bug               |               Status:  new
        Priority:  highest           |            Milestone:  8.8.1
       Component:  Compiler          |              Version:  8.2.1
      Resolution:                    |             Keywords:  JoinPoints
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  #14346            |  Differential Rev(s):  ​Phab:D4110,
       Wiki Page:                    |  Phab:D4189
-------------------------------------+-------------------------------------
Description changed by bgamari:

Old description:

> In Trac #14346 we proposed the new `with#` primop
> {{{#hs
> with# :: a -> (State# s -> (# State# s, b #)) -> State# s -> (# State# s,
> b #)
> }}}
> This ticket is to track progress.
>
> See ​Phab:D4110.

New description:

 In Trac #14346 we proposed the new `with#` primop
 {{{#!hs
 with# :: a -> (State# s -> (# State# s, b #)) -> State# s -> (# State# s,
 b #)
 }}}
 This ticket is to track progress.

 See ​Phab:D4110.

--

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14375#comment:21>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler