[atomics.types.generic] Remove note that tries to encourage

implementations to use the same size for atomic<T> as for T.

It's not appropriate for a note to contain "should" or implementation
encouragement of this kind. It's also bad advice.

Author: zygoloid

source/atomics.tex

@@ -1358,9 +1358,11 @@
 The specialization \tcode{atomic<bool>} is a standard-layout struct.
 
 \pnum
-\begin{note} The representation of an atomic specialization need not have the same size as its
-corresponding argument type. Specializations should have the same size whenever possible, as
-this reduces the effort required to port existing code. \end{note}
+\begin{note}
+The representation of an atomic specialization
+need not have the same size and alignment requirement as
+its corresponding argument type.
+\end{note}
 
 \rSec2[atomics.types.operations]{Operations on atomic types}