title: Can't find 'Show Call Hierarchy' in VSCode
body: <p>When I right click a function, there's no 'Show Call Hierarchy' or 'Peek Call Hierarchy'
  option whatsoever. My popup menu looks like this</p>
  <p><a href="https://i.stack.imgur.com/5kvfU.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/5kvfU.png" alt="enter image description here" /></a></p>
  <p>Then I tried Typing 'Show All Hierarchy' in command palette. This command does exist, but only gives a 'No Result' window after hitting enter.</p>
  <p>So I went to Keyboard Shortcuts page, and it looks like this
  <a href="https://i.stack.imgur.com/aXVNh.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/aXVNh.png" alt="enter image description here" /></a></p>
  <p>My questions are,</p>
  <ol>
  <li>Why can't I find 'Call Hierarchy' in popup menu while every tutorial online claims that I should have found it at this point.</li>
  <li>What does 'When' field in Keyboard Shortcut page mean? Am I missing any 'CallHierarchyProvider'?</li>
  </ol>
  <p>Addtional info:
  VSCode version 1.60, having C/C++ and Emacs Keymap extensions installed. Tried VSCode on both MacOS and Ubuntu, issue remains the same. The code base I'm currently viewing is configured with CMake.</p>
  <p>Any help is appreciated, thanks.</p>