[GHC] #9638: Speed up Data.Char.isDigit

[GHC]

#9638: Speed up Data.Char.isDigit
-------------------------------------+-------------------------------------
              Reporter:  dfeuer      |            Owner:
                  Type:  feature     |           Status:  new
  request                            |        Milestone:  7.10.1
              Priority:  normal      |          Version:  7.9
             Component:              |         Keywords:
  libraries/base                     |     Architecture:  Unknown/Multiple
            Resolution:              |       Difficulty:  Easy (less than 1
      Operating System:              |  hour)
  Unknown/Multiple                   |       Blocked By:
       Type of failure:  Runtime     |  Related Tickets:
  performance bug                    |
             Test Case:              |
              Blocking:              |
Differential Revisions:              |
-------------------------------------+-------------------------------------

Comment (by carter):

 These sound reasonable, do we have any (micro)benchmarks to validate that
 theres a meaningful improvement in performance to pay down the increased
 complexity of the implementation?

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9638#comment:3>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler