title: how to check llvm version number in windows 10
body: <p>Hi i downloaded llvm using svn checkout in windows 10.
  I want to know if its is properly installed or not and version number also. 
  I tried to do <code>llvm --help</code> or <code>llvm --version</code> .
  I am getting error </p>
  
  <blockquote>
    <p>'llvm' is not recognized as an internal or external command, operable program or batch file.</p>
  </blockquote>
  
  <p>What's wrong and how shall I proceed?</p>