LWG3762 generator::iterator::operator== should pass by reference

Author: burblebee

source/ranges.tex

@@ -15525,7 +15525,7 @@
     @\exposid{iterator}@& operator++();
     void operator++(int);
 
-    friend bool operator==(@\exposid{iterator}@ i, default_sentinel_t);
+    friend bool operator==(const @\exposid{iterator}@& i, default_sentinel_t);
 
   private:
     coroutine_handle<promise_type> @\exposid{coroutine_}@; // \expos
@@ -15613,7 +15613,7 @@
 
 \indexlibrarymember{operator==}{generator::\exposid{iterator}}%
 \begin{itemdecl}
-friend bool operator==(@\exposid{iterator}@ i, default_sentinel_t);
+friend bool operator==(const @\exposid{iterator}@& i, default_sentinel_t);
 \end{itemdecl}
 
 \begin{itemdescr}