[range.cache.latest.view] Add \ref for cache_latest_view::iterator/sentinel (#7514)

Author: hewillk

source/ranges.tex

@@ -16777,7 +16777,9 @@
 
     @\exposid{non-propagating-cache}@<@\exposid{cache-t}@> @\exposid{cache_}@;                              // \expos
 
+    // \ref{range.cache.latest.iterator}, class \tcode{cache_latest_view::\exposid{iterator}}
     class @\exposid{iterator}@;                                                     // \expos
+    // \ref{range.cache.latest.sentinel}, class \tcode{cache_latest_view::\exposid{sentinel}}
     class @\exposid{sentinel}@;                                                     // \expos
 
   public: