[GHC] #13541: Make it easier to use the gold linker

[GHC]

#13541: Make it easier to use the gold linker
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        Reporter:  bgamari           |                Owner:  (none)
            Type:  feature request   |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.0.1
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by angerman):

 A few things to note:

 - gold, does ELF only. So this should only be available and enabled if we
 are targeting elf.
 - I'd also suggest that this is only enabled by default if gcc is used. If
 clang is used or gcc /is/ clang, don't enable gold.

 I still believe that this kind of configuration should be part of the
 toolchain and not part of ghc though.
 I'm also a bit confused why gcc would not respect the LD env var.  Maybe
 someone with better knowledge of the gcc toolchain knows.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13541#comment:5>
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