[GHC] #11040: Split SRT tables on Mac OS

[GHC]

#11040: Split SRT tables on Mac OS
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           Reporter:  olsner            |             Owner:
               Type:  bug               |            Status:  new
           Priority:  normal            |         Milestone:
          Component:  Compiler          |           Version:  7.10.2
           Keywords:                    |  Operating System:  MacOS X
       Architecture:  Unknown/Multiple  |   Type of failure:  None/Unknown
          Test Case:                    |        Blocked By:
           Blocking:                    |   Related Tickets:
Differential Rev(s):                    |         Wiki Page:
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 Split off from https://phabricator.haskell.org/D1242#inline-11490

 Mac uses subsections via symbols to allow dead code stripping, but doesn't
 seem to do anything special with the SRT tables (in `HscMain.doCodeGen`),
 so either I'm missing something or Mac doesn't actually get much useful
 dead code stripping at all from the subsections feature because the SRT
 tables would keep everything alive.

 Perhaps Mac should just always do SRT splitting.

 Looks like you need to manually add `-optl-Wl,-dead_strip` to test this,
 since that's not enabled by default.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11040>
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