tests: add overflow test

This test case is a reduction from the `hwc` crate on GitHub, following a
crater run. It passes with the next solver but fails on the current
solver due to a known limitation of the current solver. It starts fails
on the current solver with the `sized_hierarchy` changes because `?Sized`
is now a proper bound.

1 files changed, 21 insertions, 0 deletions

diff --git a/tests/ui/sized-hierarchy/overflow.rs b/tests/ui/sized-hierarchy/overflow.rs
new file mode 100644
index 00000000000..e1af4885e53
--- /dev/null
+++ b/tests/ui/sized-hierarchy/overflow.rs
@@ -0,0 +1,21 @@
+//@ compile-flags: --crate-type=lib
+//@ revisions: current next
+//@ ignore-compare-mode-next-solver (explicit revisions)
+//@[next] check-pass
+//@[next] compile-flags: -Znext-solver
+
+use std::marker::PhantomData;
+
+trait ParseTokens {
+    type Output;
+}
+impl<T: ParseTokens + ?Sized> ParseTokens for Box<T> {
+    type Output = ();
+}
+
+struct Element(<Box<Box<Element>> as ParseTokens>::Output);
+//[current]~^ ERROR overflow evaluating
+impl ParseTokens for Element {
+//[current]~^ ERROR overflow evaluating
+    type Output = ();
+}