[GHC] #15228: Remove use of showSDocUnsafe in extending_ghc.rst

[GHC]

#15228: Remove use of showSDocUnsafe in extending_ghc.rst
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        Reporter:  mpickering        |                Owner:  (none)
            Type:  task              |               Status:  closed
        Priority:  normal            |            Milestone:  8.6.1
       Component:  Compiler          |              Version:  8.4.3
      Resolution:  fixed             |             Keywords:  newcomer
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D4815
       Wiki Page:                    |
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Comment (by Ben Gamari <ben@…>):

 In [changeset:"d24e73adf7fb33e2c94b7b6c43fe9feb9b23c3a6/ghc" d24e73a/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="d24e73adf7fb33e2c94b7b6c43fe9feb9b23c3a6"
 Replace `showSDocUnsafe` with `showSDoc` in extending_ghc.rst

 ... and fix compile errors.

 Replace the usage of `showSDocUnsafe` with `showSDoc dflags`
 in example code in extending_ghc.rts.

 This example contains several compile errors (missing import
 and syntax error), this patch also fixes that.

 Test Plan: [skip ci]

 Reviewers: bgamari, mpickering

 Reviewed By: mpickering

 Subscribers: mpickering, rwbarton, thomie, carter

 GHC Trac Issues: #15228

 Differential Revision: https://phabricator.haskell.org/D4815
 }}}

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15228#comment:3>
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