Add a regression test for https://github.com/rust-lang/rust/issues/88649

src/test/ui/consts/issue-88649.rs

@@ -0,0 +1,18 @@
+// check-pass
+#![crate_type = "lib"]
+
+enum Foo {
+    Variant1(bool),
+    Variant2(bool),
+}
+
+const _: () = {
+    let mut n = 0;
+    while n < 2 {
+        match Foo::Variant1(true) {
+            Foo::Variant1(x) | Foo::Variant2(x) if x => {}
+            _ => {}
+        }
+        n += 1;
+    }
+};