[dcl.pre] Fix example's error message to apply to "implementations where sizeof(int) > 1"

Author: burblebee

source/declarations.tex

@@ -281,7 +281,7 @@
 
 void g(char c) {
   f(0);                                 // OK
-  f(c);                                 // error: must be int-sized
+  f(c);                                 // error on implementations where \tcode{sizeof(int) > 1}: must be \tcode{int}-sized
 }
 \end{codeblock}
 \end{example}