Compile typescript without transpiling async functions
<p>Is there a way to use the TypeScript compiler only to remove type annotations, but not transpiling async functions? Something like a <code>{ target: 'esInfinite' }</code> option? The reason is: There are browsers that already support async functions, so I wish to have a build target where those functions are not affected.</p>

<p>example input:</p>

<pre><code>async function foo(a : number) : Promise&lt;void&gt; {}
</code></pre>

<p>example output:</p>

<pre><code>async function foo(a) {}
</code></pre>