[cpp] Change indirect redirect from '#' to '# operator' (and same for ##).

Author: Eelis

source/preprocessor.tex

@@ -768,7 +768,7 @@
 
 \rSec2[cpp.stringize]{The \tcode{\#} operator}%
 \indextext{\#\#0 operator@\tcode{\#} operator}%
-\indextext{stringize|see{\tcode{\#}}}
+\indextext{stringize|see{\tcode{\#} operator}}
 
 \pnum
 Each
@@ -815,7 +815,7 @@
 
 \rSec2[cpp.concat]{The \tcode{\#\#} operator}%
 \indextext{\#\#1 operator@\tcode{\#\#} operator}%
-\indextext{concatenation!macro argument|see{\tcode{\#\#}}}
+\indextext{concatenation!macro argument|see{\tcode{\#\#} operator}}
 
 \pnum
 A