fix(debuginfo): disable overflow check for recursive non-enum types

compiler/rustc_codegen_llvm/src/debuginfo/metadata/type_map.rs

@@ -285,8 +285,8 @@ pub(super) fn build_type_with_children<'ll, 'tcx>(
         //     Item(T),
         // }
         // ```
-        let is_expanding_recursive =
-            debug_context(cx).adt_stack.borrow().iter().any(|(parent_def_id, parent_args)| {
+        let is_expanding_recursive = adt_def.is_enum()
+            && debug_context(cx).adt_stack.borrow().iter().any(|(parent_def_id, parent_args)| {
                 if def_id == *parent_def_id {
                     args.iter().zip(parent_args.iter()).any(|(arg, parent_arg)| {
                         if let (Some(arg), Some(parent_arg)) = (arg.as_type(), parent_arg.as_type())

tests/codegen-llvm/debuginfo-cyclic-structure.rs

@@ -0,0 +1,32 @@
+//@ compile-flags:-g -Copt-level=0 -C panic=abort
+
+// Check that debug information exists for structures containing loops (cyclic references).
+// Previously it may incorrectly prune member information during recursive type inference check.
+
+// CHECK: !DICompositeType(tag: DW_TAG_structure_type, name: "Arc<debuginfo_cyclic_structure::Inner<alloc::sync::Arc<debuginfo_cyclic_structure::Handle{{.*}}elements: ![[FIELDS:[0-9]+]]
+// CHECK: ![[FIELDS]] = !{!{{.*}}}
+// CHECK-NOT: ![[FIELDS]] = !{}
+
+#![crate_type = "lib"]
+
+use std::mem::MaybeUninit;
+use std::sync::Arc;
+
+struct Inner<T> {
+    buffer: Box<MaybeUninit<T>>,
+}
+struct Shared {
+    shared: Arc<Inner<Arc<Handle>>>,
+}
+struct Handle {
+    shared: Shared,
+}
+struct Core {
+    inner: Arc<Inner<Arc<Handle>>>,
+}
+
+#[no_mangle]
+extern "C" fn test() {
+    let с = Core { inner: Arc::new(Inner { buffer: Box::new(MaybeUninit::uninit()) }) };
+    std::hint::black_box(с);
+}