title: How can I get a clang::QualType from a string?
body: <p>I'm working on a custom checker for the clang static analyzer that checks for incorrect use of CPython APIs.  I've made some progress, but I'm stuck: how can I get a <code>clang::QualType</code> value given the name of a type?</p>
  
  <p>For example, I'd like to write something like this:</p>
  
  <pre><code>QualType ty = findTheTypeNamed("Py_ssize_t");
  </code></pre>
  
  <p>I've spent time looking at the code for <code>clang::ASTContext</code> and <code>clang::QualType</code>, but I'm lost.</p>
  
  <p>How can I get a <code>clang::QualType</code> from the name of a type?</p>