title: Make 'git' assume I'm no longer changing anything
body: <p>I'm working on Windows and commands like <code>git status</code> are slow on my medium-size repository.</p>
  
  <p>I have finished implementing my feature (i.e. done with changes), and now I'm staging my changes (i.e. adding all the hunks relevant to the feature).</p>
  
  <p>Can I make git use its cache for <code>git status</code> (and all other recursive lstat operations) and assume I'm not changing anything else?</p>
  
  <p>P.S. I understand <code>git update-index --assume-unchanged</code> can be helpful somehow.</p>