[GHC] #11218: Provide `-W(no-)` aliases for `-f(no-)warn` warning flags

[GHC]

#11218: Provide `-W(no-)` aliases for `-f(no-)warn` warning flags
-------------------------------------+-------------------------------------
        Reporter:  hvr               |                Owner:
            Type:  feature request   |               Status:  closed
        Priority:  high              |            Milestone:  8.0.1
       Component:  Compiler          |              Version:
      Resolution:  fixed             |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D1613
       Wiki Page:  Design/Warnings   |
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Comment (by Herbert Valerio Riedel <hvr@…>):

 In [changeset:"437ebdda48e7a32fe1bea49cb503f456a0152a36/ghc" 437ebdd/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="437ebdda48e7a32fe1bea49cb503f456a0152a36"
 Start using `-W` instead of `-f(no-)warn` in some places

 This replaces some occurences of `-f(no-)warn` with the new `-W`-aliases
 introduced via 2206fa8cdb120932 / #11218, in cases which are guaranteed
 to be invoked with recent enough GHC (i.e. the stage1+ GHC).

 After this commit, mostly the compiler and the testsuite remain using
 `-f(wo-)warn...` because the compiler needs to be bootstrappable with
 older GHCs, while for the testsuite it's convenient to be able to quickly
 compare the behavior to older GHCs (which may not support the new flags
 yet).

 The compiler-part can be updated to use the new flags once GHC 8.3
 development
 starts.

 Reviewed By: quchen

 Differential Revision: https://phabricator.haskell.org/D1637
 }}}

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11218#comment:5>
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