Auto merge of #55859 - pietroalbini:rollup, r=kennytm

Rollup of 17 pull requests

Successful merges:

 - #55630 (resolve: Filter away macro prelude in modules with `#[no_implicit_prelude]` on 2018 edition)
 - #55687 (Take supertraits into account when calculating associated types)
 - #55745 (Convert `outlives_components`' return value to a `SmallVec` outparam.)
 - #55764 (Fix Rc/Arc allocation layout)
 - #55792 (Prevent ICE in const-prop array oob check)
 - #55799 (Removed unneeded instance of `// revisions` from a lint test)
 - #55800 (Fix ICE in `return_type_impl_trait`)
 - #55801 (NLL: Update box insensitivity test)
 - #55802 (Don't inline virtual calls (take 2))
 - #55816 (Use `SmallVec` to avoid allocations in `from_decimal_string`.)
 - #55819 (Typecheck patterns of all match arms first, so we get types for bindings)
 - #55822 (ICE with #![feature(nll)] and elided lifetimes)
 - #55828 (Add missing `rustc_promotable` attribute to unsigned `min_value` and `max_value`)
 - #55839 (Fix docstring spelling mistakes)
 - #55844 (Fix documentation typos.)
 - #55845 (Set BINARYEN_TRAP_MODE=clamp)
 - #55856 (rustdoc: refactor: move all static-file include!s into a single module)

2 files changed, 8 insertions, 4 deletions

diff --git a/src/liballoc/rc.rs b/src/liballoc/rc.rs
index 45f035ad04f..bb52d7990ff 100644
--- a/src/liballoc/rc.rs
+++ b/src/liballoc/rc.rs
@@ -672,14 +672,16 @@ impl<T: ?Sized> Rc<T> {
         // Previously, layout was calculated on the expression
         // `&*(ptr as *const RcBox<T>)`, but this created a misaligned
         // reference (see #54908).
-        let (layout, _) = Layout::new::<RcBox<()>>()
-            .extend(Layout::for_value(&*ptr)).unwrap();
+        let layout = Layout::new::<RcBox<()>>()
+            .extend(Layout::for_value(&*ptr)).unwrap().0
+            .pad_to_align().unwrap();
 
         let mem = Global.alloc(layout)
             .unwrap_or_else(|_| handle_alloc_error(layout));
 
         // Initialize the RcBox
         let inner = set_data_ptr(ptr as *mut T, mem.as_ptr() as *mut u8) as *mut RcBox<T>;
+        debug_assert_eq!(Layout::for_value(&*inner), layout);
 
         ptr::write(&mut (*inner).strong, Cell::new(1));
         ptr::write(&mut (*inner).weak, Cell::new(1));
diff --git a/src/liballoc/sync.rs b/src/liballoc/sync.rs
index 2c396b3b06b..b63b3684964 100644
--- a/src/liballoc/sync.rs
+++ b/src/liballoc/sync.rs
@@ -575,14 +575,16 @@ impl<T: ?Sized> Arc<T> {
         // Previously, layout was calculated on the expression
         // `&*(ptr as *const ArcInner<T>)`, but this created a misaligned
         // reference (see #54908).
-        let (layout, _) = Layout::new::<ArcInner<()>>()
-            .extend(Layout::for_value(&*ptr)).unwrap();
+        let layout = Layout::new::<ArcInner<()>>()
+            .extend(Layout::for_value(&*ptr)).unwrap().0
+            .pad_to_align().unwrap();
 
         let mem = Global.alloc(layout)
             .unwrap_or_else(|_| handle_alloc_error(layout));
 
         // Initialize the ArcInner
         let inner = set_data_ptr(ptr as *mut T, mem.as_ptr() as *mut u8) as *mut ArcInner<T>;
+        debug_assert_eq!(Layout::for_value(&*inner), layout);
 
         ptr::write(&mut (*inner).strong, atomic::AtomicUsize::new(1));
         ptr::write(&mut (*inner).weak, atomic::AtomicUsize::new(1));