[expr.prim.id.general] Add missing semicolon in example (#4956)

Author: Erich Keane

source/expressions.tex

@@ -1370,7 +1370,7 @@
 \begin{codeblock}
 template<typename T> struct A {
   static void f(int) requires false;
-}
+};
 
 void g() {
   A<int>::f(0);                         // error: cannot call \tcode{f}