Add regression test for rust-lang#73431

Author: ecstatic-morse

src/test/ui/consts/const_in_pattern/issue-73431.rs

@@ -0,0 +1,29 @@
+// run-pass
+
+// Regression test for https://github.com/rust-lang/rust/issues/73431.
+
+pub trait Zero {
+    const ZERO: Self;
+}
+
+impl Zero for usize {
+    const ZERO: Self = 0;
+}
+
+impl<T: Zero> Zero for Wrapper<T> {
+    const ZERO: Self = Wrapper(T::ZERO);
+}
+
+#[derive(Debug, PartialEq, Eq)]
+pub struct Wrapper<T>(T);
+
+fn is_zero(x: Wrapper<usize>) -> bool {
+    match x {
+        Zero::ZERO => true,
+        _ => false,
+    }
+}
+
+fn main() {
+    let _ = is_zero(Wrapper(42));
+}