Disable Ar.wipeMetadata for AIX
Disable Ar.wipeMetadata for AIX

AIX uses its own `ar` format variant (with a different header),
which causes Cabal to abort with

  Distribution.Simple.Program.Ar.wipeMetadata: Bad global header

This patch simply disables this non-essential operation for AIX.

trskop/cabal,mydaum/cabal,gbaz/cabal,randen/cabal,sopvop/cabal,Heather/cabal,headprogrammingczar/cabal,kolmodin/cabal,bennofs/cabal,gbaz/cabal,martinvlk/cabal,sopvop/cabal,randen/cabal,garetxe/cabal,lukexi/cabal,sopvop/cabal,bennofs/cabal,kolmodin/cabal,thomie/cabal,garetxe/cabal,trskop/cabal,edsko/cabal,themoritz/cabal,lukexi/cabal,thomie/cabal,headprogrammingczar/cabal,mydaum/cabal,Heather/cabal,martinvlk/cabal,themoritz/cabal,edsko/cabal,themoritz/cabal