Develop toolchain based on llvm for Cpu0 processor
BUILD steps:
Pre-install: https://github.com/Jonathan2251/lbd/README.rst
$ pwd
$ $HOME/git
$ git clone https://github.com/Jonathan2251/lbt
$ cd lbt/exlbt
$ bash build-cpu0-lbt.sh
$ bash newlib-cpu0.sh
CHECK step:
$ pwd
$ $HOME/git/lbt
$ bash check.sh