Added test for rust-lang#97732

Author: Kixiron

src/test/ui/unsized/issue-97732.rs

@@ -0,0 +1,23 @@
+// check-pass
+
+#![feature(coerce_unsized)]
+
+// Ensure that unsizing structs that contain ZSTs at non-zero offsets don't ICE
+
+use std::ops::CoerceUnsized;
+
+#[repr(C)]
+pub struct BoxWithZstTail<T: ?Sized>(Box<T>, ());
+
+impl<S: ?Sized, T: ?Sized> CoerceUnsized<BoxWithZstTail<T>> for BoxWithZstTail<S> where
+    Box<S>: CoerceUnsized<Box<T>>
+{
+}
+
+pub fn noop_dyn_upcast_with_zst_tail(
+    b: BoxWithZstTail<dyn Send + Sync>,
+) -> BoxWithZstTail<dyn Send> {
+    b
+}
+
+fn main() {}