[using.linkage, handler.functions] Remove inappropriate use of \xref

The \xref-style "see also" is only meant for references to the C standard, not for references within this document.

Author: tkoeppe

source/lib-intro.tex

@@ -1392,7 +1392,8 @@
 the program prior to program startup.
 
 \indextext{startup!program}%
-\xref
+\pnum
+See also
 replacement functions~(\ref{replacement.functions}),
 runtime changes~(\ref{handler.functions}).
 
@@ -2496,19 +2497,12 @@
 A \Cpp program may install different handler functions during execution, by
 supplying a pointer to a function defined in the program or the library
 as an argument to (respectively):
-
 \begin{itemize}
-\item
-\indexlibrary{\idxcode{set_new_handler}}%
-\tcode{set_new_handler}
-\item
-\indexlibrary{\idxcode{set_terminate}}
-\tcode{set_terminate}
-
-\xref
-subclauses~\ref{alloc.errors}, Storage allocation errors, and~\ref{support.exception},
-Exception handling.
+\item \indexlibrary{\idxcode{set_new_handler}}\tcode{set_new_handler}
+\item \indexlibrary{\idxcode{set_terminate}}\tcode{set_terminate}
 \end{itemize}
+See also subclauses~\ref{alloc.errors}, Storage allocation errors, and~\ref{support.exception},
+Exception handling.
 
 \pnum
 A \Cpp program can get a pointer to the current handler function by calling the following