[GHC] #11085: Relying on the existence of CallStack in 7.10 breaks bootstrappability with 7.10.1

[GHC]

#11085: Relying on the existence of CallStack in 7.10 breaks bootstrappability with
7.10.1
-------------------------------------+-------------------------------------
        Reporter:  quchen            |                Owner:
            Type:  bug               |               Status:  patch
        Priority:  normal            |            Milestone:  8.0.1
       Component:  Compiler          |              Version:  7.10.1
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Building GHC      |  Unknown/Multiple
  failed                             |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D1472
       Wiki Page:                    |
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Comment (by Ben Gamari <ben@…>):

 In [changeset:"54884220cd8f68bcb4291cc3689d69258b835f6f/ghc"
 54884220/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="54884220cd8f68bcb4291cc3689d69258b835f6f"
 Fix bootstrapping with GHC 7.10.1

 Relying on CallStack being in GLASGOW_HASKELL >= 710 breaks
 bootstrappability with 7.10.1

 7.10.2 added the CallStack mechanism, and GHC already relies on this
 while being built. Unfortunately, it is enabled with "GLASGOW_HASKELL
 >= 710", which also applies to GHC 7.10.1, which does not have
 CallStack, and fails building the stage-1 compiler because the symbol
 is not found.

 This patch makes the CPP directive more strict, requiring **more than**
 7.10 instead of **at least**.

 Reviewers: jstolarek, austin, bgamari

 Reviewed By: bgamari

 Subscribers: thomie

 Differential Revision: https://phabricator.haskell.org/D1472

 GHC Trac Issues: #11085
 }}}

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11085#comment:4>
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