This test checks moving to the previous word boundary across multiple text nodes.
For example, when "I" and "'ll" are put in a separate text node, we should not erroneously report the previous word boundary to be between "'" and "ll".

I'll
I'll
I'll
I'll
I'll
é'll
'll
é'll
é'll
é'll
é'll
é'll
é'll
'll
'll
'll
'll
'll
'll
é'll