make minimal go build bootstrap files to build go again.

go_bootstrap.sh

#!/bin/bash
# Ensure that you have compiled the entire go source.
# set -x
set -e
[ ! -d go ] && { echo "There is no go source code here."; exit 1; }
[ -d go_bootstrap ] && { echo "You have had go_bootstrap directory."; exit 1;}
mkdir -p go_bootstrap/pkg
echo "Create go_bootstrap directory successful"
cp -r go/{bin,src} go_bootstrap/
cp -r go/pkg/{include,linux_amd64,tool} go_bootstrap/pkg/
echo "Well done, you can compile your go source code now."
echo "Run the next code manually:"
echo "cd go/src"
echo "GOROOT_BOOTSTRAP=$(pwd)/go_bootstrap ./all.bash"