XSLT Transform adjacent comments into xs:annotations in XSDs

I have a XSD that has a number of comments, which should be moved into the a xs:annotation/xs:documentation part of the preceding xs:simpleTypes or xs:complexTypes. How can I move these comments using XSLT V1.0 or XSLT V2.0?

Example input XSD:

<?xml version="1.0" encoding="UTF-8"?>
<xs:simpleType name="ligula">
    <xs:restriction base="xs:string"/>
</xs:simpleType>
<xs:simpleType name="ultricies">
    <xs:restriction base="xs:integer"/>
</xs:simpleType>
<!--
Lorem ipsum dolor sit amet, consectetuer adipiscing elit. 
Aenean commodo ligula eget dolor. Aenean massa. Cum 
-->
<xs:simpleType name="neque">
    <xs:restriction base="xs:string"/>
</xs:simpleType>
<xs:simpleType name="tincidunt">
    <xs:restriction base="xs:string"/>
</xs:simpleType>
<!-- ligula, porttitor eu, consequat vitae, eleifend ac, enim.  -->
<!-- Etiam sit amet orci eget eros faucibus tincidunt. Duis leo. Sed.  -->
<!-- Integer tincidunt. Cras dapibus. Vivamus elementum  -->
</xs:schema>

The output XSD should be:

<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:xs="http://ift.tt/tphNwY">
    <xs:simpleType name="ligula">
        <xs:restriction base="xs:string"/>
    </xs:simpleType>
    <xs:simpleType name="ultricies">
        <xs:annotation>
            <xs:documentation>Lorem ipsum dolor sit amet, consectetuer adipiscing elit. 
            Aenean commodo ligula eget dolor. Aenean massa. Cum</xs:documentation>
        </xs:annotation>
        <xs:restriction base="xs:integer"/>
    </xs:simpleType>
    <xs:simpleType name="neque">
        <xs:restriction base="xs:string"/>
    </xs:simpleType>
    <xs:simpleType name="tincidunt">
        <xs:annotation>
            <xs:documentation>ligula, porttitor eu, consequat vitae, eleifend ac, enim</xs:documentation>
            <xs:documentation>Etiam sit amet orci eget eros faucibus tincidunt. Duis leo. Sed.</xs:documentation>
            <xs:documentation>Integer tincidunt. Cras dapibus. Vivamus elementum</xs:documentation>
        </xs:annotation>
        <xs:restriction base="xs:string"/>
    </xs:simpleType>
</xs:schema>

Many thanks in advance.