[arch-haskell] Package INSTALL scriptlets do not generate a working haddock index (gen_contents_index broken)

[Matthew Cox]

The /usr/share/doc/ghc/html/libraries/gen_contents_index script is
broken and causes haddock to emit broken links in the resulting
documentation index for the local ghc pkg tree. Here's the fix:

    -        NAME_VERSION=`echo "$HADDOCK_FILE" | sed 's#/.*##'`
    -        HADDOCK_ARG="--read-interface=${NAME_VERSION},$HADDOCK_FILE"
    +        HADDOCK_ARG="--read-interface=$(dirname
$HADDOCK_FILE),$HADDOCK_FILE"

The eager match on sed causes it to strip all but the first component
of the package documentation path.

Presumably this is broken upstream and needs to be fixed by them, but
I'd like to confirm it's not caused by us before I pester the ghc-dev
list.

Matt