Say that dereferencing a pointer to a ZST is no longer undefined
The new rules were tracked in
https://github.com/rust-lang/rust/issues/117945
The corresponding update to the Reference was
https://github.com/rust-lang/reference/pull/1541
diff --git a/src/exotic-sizes.md b/src/exotic-sizes.md
index 5e6a395..a93ab4a 100644
--- a/src/exotic-sizes.md
+++ b/src/exotic-sizes.md
@@ -106,9 +106,9 @@
and allocators typically [require a non-zero size][alloc].
Note that references to ZSTs (including empty slices), just like all other
-references, must be non-null and suitably aligned. Dereferencing a null or
-unaligned pointer to a ZST is [undefined behavior][ub], just like for any other
-type.
+references, must be non-null and suitably aligned. However, dereferencing a
+null pointer to a ZST is not [undefined behavior][ub], unlike pointers to
+other types.
[alloc]: ../std/alloc/trait.GlobalAlloc.html#tymethod.alloc
[ub]: what-unsafe-does.html
