P3923R0: Re NB US 147-240 (C++26 CD)

Fixes NB US 147-240 (C++26 CD).

Author: eisenwave

source/containers.tex

@@ -8835,6 +8835,8 @@
 \effects
 If \tcode{addressof(x) == this} is \tcode{true},
 the behavior is erroneous and there are no effects.
+If an exceptions is thrown,
+there are no effects.
 Otherwise, inserts the contents of \tcode{x} into \tcode{*this} and
 \tcode{x} becomes empty.
 Pointers and references to the moved elements of \tcode{x}