I realized that the refactor to use ReactDebugCurrentFrame as a decoupled stack frame for error messages is not reentrant: https://github.com/facebook/react/pull/10105/files#r127573520

Fiber is not reentrant but other renderers might be. The synchronous server renderer is atm.

We should add tests for warnings between renderers, such as calling a server-render from within a client render, and update the set/reset callsites to use push/pop instead to account for that.

return <g>{props.children}</g>;
    }
    expect(() =>
      ReactDOMServer.renderToStaticMarkup(
        <div>
          <inPUT />
          <svg>
            <CompositeG>
              <linearGradient />