Don't drop annotated comments in wrappers

HTML like <td><span>Foo<!--bar--></span></td> would lose the comment
when converting to linmod, and so we'd drop the comment when converting
back to HTML.

This happened because we were queueing up meta items to possibly move
them and their whitespace out of the wrapper paragraph even if we were
inside of an annotation and there was no way we could move things out
at all. The fix is simply to detect these case and not queue up meta
items in that case.

[12:11]	marktraceur	Let the comments hit the floor, let the comments hit the floor
[12:11]	marktraceur	(to the tune of the Drowning Pool "Let the Bodies Hit the Floor")

Bug: 50071
Change-Id: I5a844e2e0655bc1db152b3805718324ca0bb04df
Merge "Don't drop annotated comments in wrappers"