function hasAsyncAwaitSupport() {
	var bool;
	try {
		evil( '"use strict"; async () => {}' );
		bool = true;
	} catch ( err ) { // eslint-disable-line no-unused-vars
		bool = false;
	}
	return bool;
}
Tests for native `async/await` support.

@returns {boolean} boolean indicating if an environment has native `async`/`await` support

@example
var bool = hasAsyncAwaitSupport();
if ( bool ) {
    console.log( 'Environment has native async/await support.' );
} else {
    console.log( 'Environment lacks native async/await support.' );
}