When setting boolean attributes on Web Components
`<x-search somebool name={this.props.name} />`
they get rendered as attribute/value pairs instead
`<x-search somebool="true" name={this.props.name}>`

This causes problems with some AMP components, for eg. `<amp-iframe />` which has a `resizable` attribute that gets rendered as `resizable="true"`. This results in non valid AMP content and developers crying with blood tears on their keyboards :)
> The attribute 'resizable' in tag 'amp-iframe' is set to the invalid value 'true'. (see https://www.ampproject.org/docs/reference/components/amp-iframe)

Is there any reason for the current behaviour? Will changing this break something else?
switch (propKey) {
        case 'children':
        case 'dangerouslySetInnerHTML':
          throw new Error(
            `${tag} is a self-closing tag and must neither have \`children\` nor ` +
              'use `dangerouslySetInnerHTML`.',
          );
        
        default:
          pushAttribute(target, responseState, propKey, propValue);
          break;
      }
    }
  }
  target.push(endOfStartTagSelfClosing);
  return null;
}
function pushStartMenuItem(
  target: Array<Chunk | PrecomputedChunk>,
  props: Object,
  responseState: ResponseState,
): ReactNodeList {
  target.push(startChunkForTag('menuitem'));
  for (const propKey in props) {
    if (hasOwnProperty.call(props, propKey)) {
      const propValue = props[propKey];
      if (propValue == null) {
        continue;
      }
      switch (propKey) {