[cpp.replace] Style 'replacement-list' as a grammar term

Author: tkoeppe

source/preprocessor.tex

@@ -623,7 +623,7 @@
 
 \pnum
 \indextext{__VA_ARGS__@\mname{VA_ARGS}}%
-The identifier \mname{VA_ARGS} shall occur only in the replacement-list
+The identifier \mname{VA_ARGS} shall occur only in the \grammarterm{replacement-list}
 of a function-like macro that uses the ellipsis notation in the parameters.
 
 \pnum