[dcl.init.list] Fix misuses of \grammarterm. (#1550)

Author: cpplearner

source/declarators.tex

@@ -3729,7 +3729,7 @@
 \indextext{initialization!list-initialization|(}
 
 \pnum
-\grammarterm{List-initialization} is initialization of an object or reference from a
+\defnx{List-initialization}{list-initialization} is initialization of an object or reference from a
 \grammarterm{braced-init-list}. Such an initializer is called an \term{initializer
 list}, and the comma-separated \grammarterm{initializer-clause}{s} of the list are
 called the \term{elements} of the initializer list. An initializer list may be empty.
@@ -3766,7 +3766,7 @@
 \end{example} \end{note}
 
 \pnum
-A constructor is an \grammarterm{initializer-list constructor} if its first parameter is
+A constructor is an \defn{initializer-list constructor} if its first parameter is
 of type \tcode{std::initializer_list<E>} or reference to possibly cv-qualified
 \tcode{std::initializer_list<E>} for some type \tcode{E}, and either there are no other
 parameters or else all other parameters have default arguments (\ref{dcl.fct.default}).