Auto merge of #39563 - frewsxcv:rollup, r=frewsxcv

Rollup of 19 pull requests

- Successful merges: #38518, #38921, #38959, #38983, #39009, #39107, #39193, #39289, #39312, #39393, #39442, #39443, #39453, #39454, #39471, #39477, #39478, #39527, #39552
- Failed merges:

1 files changed, 6 insertions, 0 deletions

diff --git a/src/libcoretest/iter.rs b/src/libcoretest/iter.rs
index 6d02f76c33d..c7833dbd156 100644
--- a/src/libcoretest/iter.rs
+++ b/src/libcoretest/iter.rs
@@ -192,6 +192,12 @@ fn test_iterator_enumerate_count() {
 }
 
 #[test]
+fn test_iterator_filter_count() {
+    let xs = [0, 1, 2, 3, 4, 5, 6, 7, 8];
+    assert_eq!(xs.iter().filter(|&&x| x % 2 == 0).count(), 5);
+}
+
+#[test]
 fn test_iterator_peekable() {
     let xs = vec![0, 1, 2, 3, 4, 5];
     let mut it = xs.iter().cloned().peekable();