title: llc has no debug or -view-dag-combine1-dags option
body: <p>I have <code>llc</code> program installed on my computer via package manager (of course I have LLVM installed, 6.0.0 version). Also, I have it built from sources. What I want is to view DAGs, generated by llvm. But, unfortunately, I don't have any of options like <code>-debug</code>, <code>-view-dag-combine1-dags</code> and etc on both versions of <code>llc</code>. This drives me crazy since it is written everywhere, that this flags should help me, but it is not mentioned what to do if I don't have them. In help and man, there are no such options. I have graphviz, dot and gv installed, it should not be the problem.</p>
  
  <p>Version of compiled <code>llc</code>.</p>
  
  <pre><code>./llc -version
  LLVM (http://llvm.org/):
  LLVM version 7.0.0svn
  Optimized build.
  Default target: x86_64-unknown-linux-gnu
  Host CPU: broadwell
  
  Registered Targets:
     and targets...
  </code></pre>
  
  <p>I've built it with RelWithDebugInfo flag, maybe I should've built it with Debug flag? Or is there any flag in cmake, that I should enable? I believe that I've googled enough and I couldn't find any information.</p>