[basic.fundamental] Demote normatively redundant sentences to a note

Author: lprv

source/basic.tex

@@ -5657,10 +5657,12 @@
 
 \pnum
 The types denoted by \cv~\tcode{std::nullptr_t} are distinct types.
+\tcode{\keyword{sizeof}(std::nullptr_t)} shall be equal to \tcode{\keyword{sizeof}(\keyword{void}*)}.
+\begin{note}
 A prvalue of type \tcode{std::nullptr_t} is a null pointer
-constant\iref{conv.ptr}. Such values participate in the pointer and the
+constant\iref{conv.ptr}. Such expressions participate in the pointer and the
 pointer-to-member conversions\iref{conv.ptr,conv.mem}.
-\tcode{\keyword{sizeof}(std::nullptr_t)} shall be equal to \tcode{\keyword{sizeof}(\keyword{void}*)}.
+\end{note}
 
 \pnum
 A value of type \tcode{std::meta::info} is called a \defn{reflection}.