Not all components build correctly on all targets and the release
script had no way to disable them other than editing the script locally.
This change provides a way to disable the test-suite, compiler-rt and
the libraries, as well as allowing you to re-run on the same directory
without checking out all sources again.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242919 91177308-0d34-0410-b5e6-96231b3b80d8
