Get rid of PERL dependency of `ghc-split`
ghc-split is a ~280 SLOC (literate) Perl script and it's needed at runtime by GHC. Which means that we depend on a Perl interpreter, and since Windows usually doesn't have one installed by default, we need to bundle a Perl interpreter w/ the GHC binary Windows distribution for convenience.
ghc-splittool in Haskell, or
ghc-splitfunctionality into GHC proper