[directory_iterator.*] shorten stable names to [dir.itr.*]

Author: jwakely

source/iostreams.tex

@@ -10148,7 +10148,7 @@
   // \ref{class.directory_iterator}, directory iterators
   class directory_iterator;
 
-  // \ref{directory_iterator.nonmembers}, range access for directory iterators
+  // \ref{dir.itr.nonmembers}, range access for directory iterators
   directory_iterator begin(directory_iterator iter) noexcept;
   directory_iterator end(const directory_iterator&) noexcept;
 
@@ -12642,7 +12642,7 @@
     using pointer           = const directory_entry*;
     using reference         = const directory_entry&;
 
-    // \ref{directory_iterator.members}, member functions
+    // \ref{dir.itr.members}, member functions
     directory_iterator() noexcept;
     explicit directory_iterator(const path& p);
     directory_iterator(const path& p, directory_options options);
@@ -12715,7 +12715,7 @@
 POSIX \tcode{readdir_r}.
 \end{note}
 
-\rSec3[directory_iterator.members]{\tcode{directory_iterator} members}
+\rSec3[dir.itr.members]{\tcode{directory_iterator} members}
 
 \indexlibrary{\idxcode{directory_iterator}!constructor}%
 \begin{itemdecl}
@@ -12808,7 +12808,7 @@
 
 \end{itemdescr}
 
-\rSec3[directory_iterator.nonmembers]{\tcode{directory_iterator} non-member functions}
+\rSec3[dir.itr.nonmembers]{\tcode{directory_iterator} non-member functions}
 
 \pnum
 These functions enable range access for \tcode{directory_iterator}.