[GHC] #16253: Offer a shorthand for `--skip=_build/stage$n/compiler/.dependencies.mk`

[GHC]

#16253: Offer a shorthand for `--skip=_build/stage$n/compiler/.dependencies.mk`
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        Reporter:  sgraf             |                Owner:  (none)
            Type:  task              |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Build System      |              Version:  8.6.3
  (Hadrian)                          |
      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 alpmestan):

 Self-note: the relevant code lives in
 https://gitlab.haskell.org/ghc/ghc/blob/master/compiler/main/DriverMkDepend.hs.
 The simplest approach is probably to refine that `GhcMode` to be either
 transitive or not. When transitive, we'd take the current code path, when
 not, we'd take the new one that just looks at and reports the immediate
 dependencies. The former would still be exposed under `-M` and the new one
 under some other flag (any suggestion is welcome).

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/16253#comment:16>
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