title: makefile: remove duplicate words without sorting
body: <p>Is there a possibility to remove duplicates in a list of words without sorting <em>in a makefile</em>?</p>
  
  <pre><code>$(sort foo bar lose)
  </code></pre>
  
  <p>does remove duplicates (which is for me the main functionality in this case), but also sorts (for me an unfortunate side effect in this case). I want to avoid that.</p>
  
  <p>[update]</p>
  
  <p><strong>bobbogo</strong>'s answer works very nicely. Just remember to use <code>define uniq</code> for v3.81 and (did not check this) <code>define uniq =</code> for later versions.</p>
  
  <p><strong>larsmans</strong>' answer works very nicely too <em>if</em> your record separator is not a space, e.g. if you want to remove duplicates from <code>_foo_bar_lose_lose_bar_baz_</code> or the like. Just remember to use the <code>RS</code> and <code>ORS</code> awk options instead of <code>tr</code>, and wrap it all with <code>$(firstword  $(shell ... ))</code></p>