index semantic isn't restricted to body

[mattgarrish]

There's an index test (index-declaration-body-error.xhtml) that throws an error if epub:type=index isn't on the body element when there's other content in the file, but this seems to be the opposite of what the specification says:

If an index, or a part of an index, is embedded within a content document that also contains other types of content, any [HTML5] sectioning content element may be used to wrap it (for example, <section epub:type="index">).