Add `PhantomData` marker for dropck to `BTreeMap`

closes #99408

2 files changed, 21 insertions, 3 deletions

diff --git a/src/test/ui/issues/issue-72554.rs b/src/test/ui/issues/issue-72554.rs
index 47aca05d778..7287639c61d 100644
--- a/src/test/ui/issues/issue-72554.rs
+++ b/src/test/ui/issues/issue-72554.rs
@@ -1,10 +1,13 @@
 use std::collections::BTreeSet;
 
 #[derive(Hash)]
-pub enum ElemDerived { //~ ERROR recursive type `ElemDerived` has infinite size
+pub enum ElemDerived {
+    //~^ ERROR recursive type `ElemDerived` has infinite size
+    //~| ERROR cycle detected when computing drop-check constraints for `ElemDerived`
     A(ElemDerived)
 }
 
+
 pub enum Elem {
     Derived(ElemDerived)
 }
diff --git a/src/test/ui/issues/issue-72554.stderr b/src/test/ui/issues/issue-72554.stderr
index a6e44be636a..3e5adcae133 100644
--- a/src/test/ui/issues/issue-72554.stderr
+++ b/src/test/ui/issues/issue-72554.stderr
@@ -3,6 +3,7 @@ error[E0072]: recursive type `ElemDerived` has infinite size
    |
 LL | pub enum ElemDerived {
    | ^^^^^^^^^^^^^^^^^^^^ recursive type has infinite size
+...
 LL |     A(ElemDerived)
    |       ----------- recursive without indirection
    |
@@ -11,6 +12,20 @@ help: insert some indirection (e.g., a `Box`, `Rc`, or `&`) to make `ElemDerived
 LL |     A(Box<ElemDerived>)
    |       ++++           +
 
-error: aborting due to previous error
+error[E0391]: cycle detected when computing drop-check constraints for `ElemDerived`
+  --> $DIR/issue-72554.rs:4:1
+   |
+LL | pub enum ElemDerived {
+   | ^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: ...which immediately requires computing drop-check constraints for `ElemDerived` again
+note: cycle used when computing drop-check constraints for `Elem`
+  --> $DIR/issue-72554.rs:11:1
+   |
+LL | pub enum Elem {
+   | ^^^^^^^^^^^^^
+
+error: aborting due to 2 previous errors
 
-For more information about this error, try `rustc --explain E0072`.
+Some errors have detailed explanations: E0072, E0391.
+For more information about an error, try `rustc --explain E0072`.