In the admin, render the Toolbar immediately, rather than waiting until the...

In the admin, render the Toolbar immediately, rather than waiting until the footer. When intensive pages take a while to load, you aren't stuck without a working admin header. fixes #20161.

git-svn-id: https://core.svn.wordpress.org/trunk@20099 1a063a9b-81f0-0310-95a4-ce76da25c4cd