Explain method-call move errors in loops

PR #73708 added a more detailed explanation of move errors that occur
due to a call to a method that takes `self`. This PR extends that logic
to work when a move error occurs due to a method call in the previous
iteration of a loop.

3 files changed, 22 insertions, 2 deletions

diff --git a/src/test/ui/moves/move-fn-self-receiver.rs b/src/test/ui/moves/move-fn-self-receiver.rs
index 6107f53fa19..946642ef6f3 100644
--- a/src/test/ui/moves/move-fn-self-receiver.rs
+++ b/src/test/ui/moves/move-fn-self-receiver.rs
@@ -69,6 +69,11 @@ fn move_out(val: Container) {
     let container = Container(vec![]);
     for _val in container.custom_into_iter() {}
     container; //~ ERROR use of moved
+
+    let foo2 = Foo;
+    loop {
+        foo2.use_self(); //~ ERROR use of moved
+    }
 }
 
 fn main() {}
diff --git a/src/test/ui/moves/move-fn-self-receiver.stderr b/src/test/ui/moves/move-fn-self-receiver.stderr
index dd263c1e906..8c509363d02 100644
--- a/src/test/ui/moves/move-fn-self-receiver.stderr
+++ b/src/test/ui/moves/move-fn-self-receiver.stderr
@@ -152,7 +152,16 @@ note: this function consumes the receiver `self` by taking ownership of it, whic
 LL |     fn custom_into_iter(self) -> impl Iterator<Item = bool> {
    |                         ^^^^
 
-error: aborting due to 11 previous errors
+error[E0382]: use of moved value: `foo2`
+  --> $DIR/move-fn-self-receiver.rs:75:9
+   |
+LL |     let foo2 = Foo;
+   |         ---- move occurs because `foo2` has type `Foo`, which does not implement the `Copy` trait
+LL |     loop {
+LL |         foo2.use_self();
+   |         ^^^^ ---------- `foo2` moved due to this method call, in previous iteration of loop
+
+error: aborting due to 12 previous errors
 
 Some errors have detailed explanations: E0382, E0505.
 For more information about an error, try `rustc --explain E0382`.
diff --git a/src/test/ui/suggestions/borrow-for-loop-head.stderr b/src/test/ui/suggestions/borrow-for-loop-head.stderr
index de342a969f4..64ce6c1e16d 100644
--- a/src/test/ui/suggestions/borrow-for-loop-head.stderr
+++ b/src/test/ui/suggestions/borrow-for-loop-head.stderr
@@ -15,8 +15,14 @@ LL |     for i in &a {
 LL |         for j in a {
    |                  ^
    |                  |
-   |                  value moved here, in previous iteration of loop
+   |                  `a` moved due to this implicit call to `.into_iter()`, in previous iteration of loop
    |                  help: consider borrowing to avoid moving into the for loop: `&a`
+   |
+note: this function consumes the receiver `self` by taking ownership of it, which moves `a`
+  --> $SRC_DIR/core/src/iter/traits/collect.rs:LL:COL
+   |
+LL |     fn into_iter(self) -> Self::IntoIter;
+   |                  ^^^^
 
 error: aborting due to 2 previous errors