Merge 2023-06 LWG Motion 13

P2013R5 Freestanding Language: Optional ::operator new

Author: tkoeppe

source/support.tex

@@ -2279,6 +2279,25 @@
 is not a valid alignment value,
 the behavior is undefined.
 
+\pnum
+On freestanding implementations,
+it is \impldef{whether freestanding default replaceable global allocation functions satisfy required behavior}
+whether the default versions of the replaceable global allocation functions
+satisfy the required behaviors
+described in \ref{new.delete.single} and \ref{new.delete.array}.
+\begin{note}
+A freestanding implementation's default versions of
+the replaceable global allocation functions
+can cause undefined behavior when invoked.
+During constant evaluation,
+the behaviors of those default versions are irrelevant,
+as those calls are omitted\iref{expr.new}.
+\end{note}
+
+\recommended
+If any of the default versions of the replaceable global allocation functions
+meet the requirements of a hosted implementation, they all should.
+
 \newcommand{\replaceabledesc}[1]{%
 A \Cpp{} program may define functions with #1 of these function signatures,
 and thereby displace the default versions defined by the