[class] Move paragraph breaks to improve vertical whitespace.

Author: zygoloid

source/classes.tex

@@ -137,14 +137,14 @@
 
 A \term{trivial class} is a class that has a default
 constructor~(\ref{class.ctor}), has no non-trivial default constructors, and is trivially copyable.
-
 \enternote In particular, a trivially copyable or trivial class does not have
 virtual functions or virtual base classes.\exitnote
 
 \indextext{class!standard-layout}%
 \indextext{standard-layout~class}%
 \pnum
 A \grammarterm{standard-layout class} is a class that:
+
 \begin{itemize}
 \item has no non-static data members of type non-standard-layout class
 (or array of such types) or reference,