Auto merge of rust-lang#131275 - workingjubilee:rollup-4yxqio3, r=workingjubilee

Rollup of 9 pull requests

Successful merges:

 - rust-lang#129517 (Compute array length from type for unconditional panic lint. )
 - rust-lang#130367 (Check elaborated projections from dyn don't mention unconstrained late bound lifetimes)
 - rust-lang#130403 (Stabilize `const_slice_from_raw_parts_mut`)
 - rust-lang#130633 (Add support for reborrowing pinned method receivers)
 - rust-lang#131105 (update `Literal`'s intro)
 - rust-lang#131194 (Fix needless_lifetimes in stable_mir)
 - rust-lang#131260 (rustdoc: cleaner errors on disambiguator/namespace mismatches)
 - rust-lang#131267 (Stabilize `BufRead::skip_until`)
 - rust-lang#131273 (Account for `impl Trait {` when `impl Trait for Type {` was intended)

r? `@ghost`
`@rustbot` modify labels: rollup

Author: bors

compiler/rustc_middle/src/ty/sty.rs

@@ -584,6 +584,16 @@ impl<'tcx> Ty<'tcx> {
         Ty::new_ref(tcx, r, ty, hir::Mutability::Not)
     }
 
+    pub fn new_pinned_ref(
+        tcx: TyCtxt<'tcx>,
+        r: Region<'tcx>,
+        ty: Ty<'tcx>,
+        mutbl: ty::Mutability,
+    ) -> Ty<'tcx> {
+        let pin = tcx.adt_def(tcx.require_lang_item(LangItem::Pin, None));
+        Ty::new_adt(tcx, pin, tcx.mk_args(&[Ty::new_ref(tcx, r, ty, mutbl).into()]))
+    }
+
     #[inline]
     pub fn new_ptr(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>, mutbl: ty::Mutability) -> Ty<'tcx> {
         Ty::new(tcx, ty::RawPtr(ty, mutbl))

compiler/rustc_mir_transform/src/known_panics_lint.rs

@@ -600,13 +600,15 @@ impl<'mir, 'tcx> ConstPropagator<'mir, 'tcx> {
             }
 
             Len(place) => {
-                let len = match self.get_const(place)? {
-                    Value::Immediate(src) => src.len(&self.ecx).discard_err()?,
-                    Value::Aggregate { fields, .. } => fields.len() as u64,
-                    Value::Uninit => match place.ty(self.local_decls(), self.tcx).ty.kind() {
-                        ty::Array(_, n) => n.try_eval_target_usize(self.tcx, self.param_env)?,
-                        _ => return None,
-                    },
+                let len = if let ty::Array(_, n) = place.ty(self.local_decls(), self.tcx).ty.kind()
+                {
+                    n.try_eval_target_usize(self.tcx, self.param_env)?
+                } else {
+                    match self.get_const(place)? {
+                        Value::Immediate(src) => src.len(&self.ecx).discard_err()?,
+                        Value::Aggregate { fields, .. } => fields.len() as u64,
+                        Value::Uninit => return None,
+                    }
                 };
                 ImmTy::from_scalar(Scalar::from_target_usize(len, self), layout).into()
             }