[GHC] #10728: Add e.g. "-N<=4" in addition to the fixed "-N4" and variable "-N" RTS options

[GHC]

#10728: Add e.g. "-N<=4" in addition to the fixed "-N4" and variable "-N" RTS
options
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        Reporter:  rrnewton          |                Owner:  MarcelineVQ
            Type:  feature request   |               Status:  patch
        Priority:  normal            |            Milestone:
       Component:  Runtime System    |              Version:  7.10.2
      Resolution:                    |             Keywords:  newcomer
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  #9221, #8224      |  Differential Rev(s):  Phab:D1650
       Wiki Page:                    |
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Comment (by hvr):

 First, the single-dash introducing a long-opt is confusing. But let's
 ignore that one for a moment.

 Moreover, in the context of `-Ndiv<n>` and `-Nsub<n>` I consider
 `-Nmax<n>` wrongly named:
 It should rather be named `-Nmin<n>` to avoid confusion:

 Intuitively, `-N<infixop><n>` denotes {{{N `infixop` <n>}}}, with the
 binary operators

 {{{#!hs
 min, max, add, sub, div, mul :: Int -> Int -> Int
 }}}

 and the obvious definitions, this would imply that `-Nmax4` means {{{N
 `max` 4}}} which is not what's implemented here.

 The description of the flag alone should rise red flags already:

 | -N'''max'''<x> chooses the '''min'''imum of processor count or x

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10728#comment:12>
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