[expr.prim.lambda.general] Add example for parsing ambiguity

Fixes NB JP 021 (C++23 DIS).

Author: jensmaurer

source/expressions.tex

@@ -1798,6 +1798,11 @@
 \begin{note}
 Such ambiguous cases cannot have valid semantics
 because the constraint expression would not have type \keyword{bool}.
+\begin{example}
+\begin{codeblock}
+auto x = []<class T> requires T::operator int [[some_attribute]] (int) { }
+\end{codeblock}
+\end{example}
 \end{note}
 
 \pnum