[any.class] Rephrase small-object optimization

Author: jensmaurer

source/utilities.tex

@@ -5114,11 +5114,12 @@
 
 \pnum
 Implementations should avoid the use of dynamically allocated memory for a small contained value.
+However, any such small-object optimization shall only be applied to types \tcode{T} for which
+\tcode{is_nothrow_move_constructible_v<T>} is \tcode{true}.
 \begin{example}
-where the object constructed is holding only an \tcode{int}.
+A contained value of type \tcode{int} could be stored in an internal buffer,
+not in separately-allocated memory.
 \end{example}
-Such small-object optimization shall only be applied to types \tcode{T} for which
-\tcode{is_nothrow_move_constructible_v<T>} is \tcode{true}.
 
 \rSec3[any.cons]{Construction and destruction}