respect line breaks around custom fragments

[gzzhanghao]

This PR aims to fix the same issue with #714

The issue still exists after setting preserveLineBreaks option.

<script>//
<% ... %>
</script>

Expected:

<script>
<% ... %>
</script>

Actual:

<script></script>

[alexlamsl]

Looking at that regex, cases like <script>\n\t<% ... %></script> might not be covered...?

Edit: never mind, I see how this can work just fine.

[alexlamsl]

As stated in #716, I think we should just aim to tackle the larger issue of having custom fragments in all sorts of locations within scripts and stylesheets, either by default or using custom processors.

[gzzhanghao]

Fixed in #720