[dcl.ref] Move an index entry closer to what it indexes.

Author: Eelis

source/declarators.tex

@@ -728,10 +728,10 @@
 is ``lvalue reference to \tcode{int}'',
 not ``lvalue reference to \tcode{const int}''.
 \exitexample
-\indextext{\idxcode{void\&}}%
 \enternote
 A reference can be thought of as a name of an object.
 \exitnote
+\indextext{\idxcode{void\&}}%
 A declarator that specifies the type
 ``reference to \textit{cv} \tcode{void}''
 is ill-formed.