title: Meson absolute path from include_directories
body: <p>In Meson, is it possible to get a string absolute path from an object created by a call to <code>include_directories</code>?</p>
  
  <p>My use case:</p>
  
  <pre class="lang-py prettyprint-override"><code>    include_dirs = include_directories('include')
      lib = library(
          'mylib',
          source_files,
          include_directories: include_dirs
      )
      run_target('analyze',
          command: ['static_analysis',
              source_files,
              '-I', include_dirs.to_abs_path(),
          ]
      )
  </code></pre>
  
  <p><code>include_dirs.to_abs_path()</code> does not exist, but I wonder if something similar is possible. Alternatively, <code>files()</code> exists(as used for <code>source_files</code> here); is there a <code>directories()</code>?</p>