title: `-Wl,` prefix to compiler flag
body: <p>I'm new to a codebase and I'm looking through a Makefile. I see several compiler flags specified with a <code>-Wl,</code> prefix (i.e. <code>-Wl,--no-undefined</code> specified). I have not encountered this syntax before and it is difficult to Google search.</p>
  
  <p>What is the prefix doing? It looks like it has to do with warnings, but I don't know and I'm hesitant to mess with it.</p>