title: What's the "discriminator" in addr2line?
body: <p>When running addr2line in some programs, I get a "discriminator N" comment at the end of the line:</p>
  
  <p><code>main at /tmp/nsievebits.c:56 (discriminator 3)</code></p>
  
  <p>The man page doesn't mention it, and a quick Google search seems to indicate mostly source code files, with no clear explanation. Is it some intentionally undocumented feature? More importantly, should I worry about it at all?</p>