Improved link to Foreign hslibs stuff.
<Para>
The foreign interface consists of language and library support. The former
is described later in <XRef LinkEnd="ffi">; the latter is outlined below,
<Para>
The foreign interface consists of language and library support. The former
is described later in <XRef LinkEnd="ffi">; the latter is outlined below,
-and detailed in the hslibs documentation.
+and detailed in <XRef LinkEnd="sec-Foreign">.
</Para>
<Sect2 id="glasgow-foreign-headers">
</Para>
<Sect2 id="glasgow-foreign-headers">