Remove obsolete cross-port script

This patch removes the obsolete cross-port script in the tree. The
script was based on the legacy Make build system which has been pruned
from the tree long ago. For hadrian, proper support for two-stage
bootstrapping onto a new unsupported platform is a work in progress in
!11444.

(cherry picked from commit 00d551bf)
(cherry picked from commit 329a26da)

distrib/cross-port

-#!/usr/bin/env bash
-
-# This script can be used to generate some unregisterised .hc files
-# for bootstrapping GHC on a new/unsupported platform.  It involves a
-# two-stage bootstrap: the first stage builds an unregisterised set of
-# libraries & RTS, and the second stage builds an unregisterised
-# compiler.  
-
-# Take the .hc files from the libraries of stage 1, and the compiler
-# of stage 2, to the target system and bootstrap from these to get a
-# working (unregisterised) compiler.
-
-set -e
-
-base=`pwd`
-
-# set this to the location of your source tree
-fptools_dir=$HOME/fptools
-
-if [ ! -f b1-stamp ]; then
-  mkdir b1
-  cd b1
-  lndir $fptools_dir
-  cd ..
-
-  cd b1
-   ./configure
-
-   # For cross-compilation, at this stage you may want to set up a source
-   # tree on the target machine, run the configure script there, and bring
-   # the resulting rts/ghcautoconf.h.autoconf file back into this tree before building
-   # the libraries.
-
-   touch mk/build.mk
-   echo "GhcUnregisterised = YES" >> mk/build.mk
-   echo "GhcLibHcOpts = -O -H32m -fvia-C -keep-hc-files" >> mk/build.mk
-   echo "GhcLibWays =" >> mk/build.mk
-
-   # We could optimise slightly by not building hslibs here.  Also, building
-   # the RTS is not necessary (and might not be desirable if we're using
-   # a ghcautoconf.h from the target system).
-   make stage1
-
-  cd ..
-
-  touch b1-stamp
-fi
-
-# exit 0
-
-if [ ! -f b2-stamp ]; then
-  mkdir b2
-  cd b2
-  lndir $fptools_dir
-  cd ..
-
-  cd b2
-   ./configure --with-ghc=$base/b1/ghc/compiler/stage1/ghc-inplace
-
-   touch mk/build.mk
-   # The bootstrapped compiler should probably generate unregisterised
-   # code too.  If you don't want it to, then comment out this line:
-   echo "GhcUnregisterised = YES" >> mk/build.mk
-   echo "SRC_HC_OPTS += -keep-hc-file -fvia-C" >> mk/build.mk
-   echo "GhcWithInterpreter = NO" >> mk/build.mk
-
-   # we just need to build the compiler and utils...
-   (cd glafp-utils && make boot && make)
-   (cd ghc && make boot)
-   (cd ghc/utils && make)
-   (cd ghc/compiler && make stage=1)
-  cd ..
-
-  touch b2-stamp
-fi