[basic.def.odr] Add punctuation (#8598)

Author: lprv

source/basic.tex

@@ -497,25 +497,25 @@
 \begin{itemize}
 \item
 \tcode{x} is a reference
-that is usable in constant expressions at $P$\iref{expr.const} or
+that is usable in constant expressions at $P$\iref{expr.const}, or
 \item
 $N$ is an element of the set of potential results of an expression $E$, where
 \begin{itemize}
 \item
 $E$ is a discarded-value expression\iref{expr.context}
-to which the lvalue-to-rvalue conversion is not applied or
+to which the lvalue-to-rvalue conversion is not applied, or
 \item
 \tcode{x} is a non-volatile object
 that is usable in constant expressions at $P$ and
-has no mutable subobjects and
+has no mutable subobjects, and
 \begin{itemize}
 \item
 $E$ is a class member access expression\iref{expr.ref}
 naming a non-static data member of reference type and
-whose object expression has non-volatile-qualified type or
+whose object expression has non-volatile-qualified type, or
 \item
 the lvalue-to-rvalue conversion\iref{conv.lval} is applied to $E$ and
-$E$ has non-volatile-qualified non-class type
+$E$ has non-volatile-qualified non-class type.
 \end{itemize}
 \end{itemize}
 \end{itemize}