Add entries to main index for 'move' and 'forward'.

We don't index library functions like this normally, but move and
forward are more fundamental than most.

Author: zygoloid

source/utilities.tex

@@ -356,6 +356,7 @@
 All functions specified in this subclause are signal-safe\iref{support.signal}.
 
 \indexlibrary{\idxcode{forward}}%
+\indextext{\idxcode{forward}}%
 \begin{itemdecl}
 template <class T> constexpr T&& forward(remove_reference_t<T>& t) noexcept;
 template <class T> constexpr T&& forward(remove_reference_t<T>&& t) noexcept;
@@ -398,6 +399,7 @@
 \end{itemdescr}
 
 \indexlibrary{\idxcode{move}!function}%
+\indextext{\idxcode{move}}%
 \begin{itemdecl}
 template <class T> constexpr remove_reference_t<T>&& move(T&& t) noexcept;
 \end{itemdecl}