Auto merge of rust-lang#92998 - Amanieu:hashbrown12, r=Mark-Simulacrum

Update hashbrown to 0.12.0

[Changelog](https://github.com/rust-lang/hashbrown/blob/master/CHANGELOG.md#v0120---2022-01-17)

Author: bors

std/Cargo.toml

@@ -19,7 +19,7 @@ libc = { version = "0.2.108", default-features = false, features = ['rustc-dep-o
 compiler_builtins = { version = "0.1.66" }
 profiler_builtins = { path = "../profiler_builtins", optional = true }
 unwind = { path = "../unwind" }
-hashbrown = { version = "0.11", default-features = false, features = ['rustc-dep-of-std'] }
+hashbrown = { version = "0.12", default-features = false, features = ['rustc-dep-of-std'] }
 std_detect = { path = "../stdarch/crates/std_detect", default-features = false, features = ['rustc-dep-of-std'] }
 
 # Dependencies of the `backtrace` crate

std/src/collections/hash/map/tests.rs

@@ -817,6 +817,7 @@ fn test_retain() {
 }
 
 #[test]
+#[cfg_attr(target_os = "android", ignore)] // Android used in CI has a broken dlmalloc
 fn test_try_reserve() {
     let mut empty_bytes: HashMap<u8, u8> = HashMap::new();
 
@@ -828,11 +829,21 @@ fn test_try_reserve() {
         "usize::MAX should trigger an overflow!"
     );
 
-    assert_matches!(
-        empty_bytes.try_reserve(MAX_USIZE / 8).map_err(|e| e.kind()),
-        Err(AllocError { .. }),
-        "usize::MAX / 8 should trigger an OOM!"
-    );
+    if let Err(AllocError { .. }) = empty_bytes.try_reserve(MAX_USIZE / 16).map_err(|e| e.kind()) {
+    } else {
+        // This may succeed if there is enough free memory. Attempt to
+        // allocate a few more hashmaps to ensure the allocation will fail.
+        let mut empty_bytes2: HashMap<u8, u8> = HashMap::new();
+        let _ = empty_bytes2.try_reserve(MAX_USIZE / 16);
+        let mut empty_bytes3: HashMap<u8, u8> = HashMap::new();
+        let _ = empty_bytes3.try_reserve(MAX_USIZE / 16);
+        let mut empty_bytes4: HashMap<u8, u8> = HashMap::new();
+        assert_matches!(
+            empty_bytes4.try_reserve(MAX_USIZE / 16).map_err(|e| e.kind()),
+            Err(AllocError { .. }),
+            "usize::MAX / 16 should trigger an OOM!"
+        );
+    }
 }
 
 #[test]