Copy GHC's config.guess/sub over libffi's versions
Copy GHC's config.guess/sub over libffi's versions

This should address #9924 as GHC's config.guess/sub versions need to be
up to date anyway.

(cherry picked from commit 9ae78b0ac20199982b994122889a04c6124e01b2)

nathyong/microghc-ghc,forked-upstream-packages-for-ghcjs/ghc,nathyong/microghc-ghc,nathyong/microghc-ghc,nathyong/microghc-ghc,forked-upstream-packages-for-ghcjs/ghc,nathyong/microghc-ghc,nathyong/microghc-ghc,nathyong/microghc-ghc,forked-upstream-packages-for-ghcjs/ghc,forked-upstream-packages-for-ghcjs/ghc,forked-upstream-packages-for-ghcjs/ghc,forked-upstream-packages-for-ghcjs/ghc,forked-upstream-packages-for-ghcjs/ghc