Auto merge of #101017 - JohnTitor:rollup-73f2fhb, r=JohnTitor

Rollup of 8 pull requests

Successful merges:

 - #99064 (distinguish the method and associated function diagnostic information)
 - #99920 (Custom allocator support in `rustc_serialize`)
 - #100034 ( Elaborate all box dereferences in `ElaborateBoxDerefs`)
 - #100076 (make slice::{split_at,split_at_unchecked} const functions)
 - #100604 (Remove unstable Result::into_ok_or_err)
 - #100933 (Reduce code size of `assert_matches_failed`)
 - #100978 (Handle `Err` in `ast::LitKind::to_token_lit`.)
 - #101010 (rustdoc: remove unused CSS for `.multi-column`)

Failed merges:

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

27 files changed, 187 insertions, 255 deletions

diff --git a/compiler/rustc_ast/src/util/literal.rs b/compiler/rustc_ast/src/util/literal.rs
index 6a02a3b56f6..69a78d165ef 100644
--- a/compiler/rustc_ast/src/util/literal.rs
+++ b/compiler/rustc_ast/src/util/literal.rs
@@ -199,7 +199,9 @@ impl LitKind {
                 let symbol = if value { kw::True } else { kw::False };
                 (token::Bool, symbol, None)
             }
-            LitKind::Err => unreachable!(),
+            // This only shows up in places like `-Zunpretty=hir` output, so we
+            // don't bother to produce something useful.
+            LitKind::Err => (token::Err, Symbol::intern("<bad-literal>"), None),
         };
 
         token::Lit::new(kind, symbol, suffix)
diff --git a/compiler/rustc_codegen_gcc/patches/0024-core-Disable-portable-simd-test.patch b/compiler/rustc_codegen_gcc/patches/0024-core-Disable-portable-simd-test.patch
index d5fa1cec061..c59a40df039 100644
--- a/compiler/rustc_codegen_gcc/patches/0024-core-Disable-portable-simd-test.patch
+++ b/compiler/rustc_codegen_gcc/patches/0024-core-Disable-portable-simd-test.patch
@@ -14,7 +14,6 @@ index 06c7be0..359e2e7 100644
 @@ -75,7 +75,6 @@
  #![feature(never_type)]
  #![feature(unwrap_infallible)]
- #![feature(result_into_ok_or_err)]
 -#![feature(portable_simd)]
  #![feature(ptr_metadata)]
  #![feature(once_cell)]
diff --git a/compiler/rustc_middle/src/mir/mod.rs b/compiler/rustc_middle/src/mir/mod.rs
index 7ab71f9009d..9da9b4e91f6 100644
--- a/compiler/rustc_middle/src/mir/mod.rs
+++ b/compiler/rustc_middle/src/mir/mod.rs
@@ -1531,6 +1531,7 @@ impl<'tcx> Place<'tcx> {
 }
 
 impl From<Local> for Place<'_> {
+    #[inline]
     fn from(local: Local) -> Self {
         Place { local, projection: List::empty() }
     }
diff --git a/compiler/rustc_mir_dataflow/src/impls/liveness.rs b/compiler/rustc_mir_dataflow/src/impls/liveness.rs
index 21132eb991f..483c1e274aa 100644
--- a/compiler/rustc_mir_dataflow/src/impls/liveness.rs
+++ b/compiler/rustc_mir_dataflow/src/impls/liveness.rs
@@ -23,12 +23,6 @@ use crate::{Analysis, AnalysisDomain, Backward, CallReturnPlaces, GenKill, GenKi
 /// [liveness]: https://en.wikipedia.org/wiki/Live_variable_analysis
 pub struct MaybeLiveLocals;
 
-impl MaybeLiveLocals {
-    fn transfer_function<'a, T>(&self, trans: &'a mut T) -> TransferFunction<'a, T> {
-        TransferFunction(trans)
-    }
-}
-
 impl<'tcx> AnalysisDomain<'tcx> for MaybeLiveLocals {
     type Domain = ChunkedBitSet<Local>;
     type Direction = Backward;
@@ -54,7 +48,7 @@ impl<'tcx> GenKillAnalysis<'tcx> for MaybeLiveLocals {
         statement: &mir::Statement<'tcx>,
         location: Location,
     ) {
-        self.transfer_function(trans).visit_statement(statement, location);
+        TransferFunction(trans).visit_statement(statement, location);
     }
 
     fn terminator_effect(
@@ -63,7 +57,7 @@ impl<'tcx> GenKillAnalysis<'tcx> for MaybeLiveLocals {
         terminator: &mir::Terminator<'tcx>,
         location: Location,
     ) {
-        self.transfer_function(trans).visit_terminator(terminator, location);
+        TransferFunction(trans).visit_terminator(terminator, location);
     }
 
     fn call_return_effect(
@@ -85,9 +79,11 @@ impl<'tcx> GenKillAnalysis<'tcx> for MaybeLiveLocals {
         _resume_block: mir::BasicBlock,
         resume_place: mir::Place<'tcx>,
     ) {
-        if let Some(local) = resume_place.as_local() {
-            trans.kill(local);
-        }
+        YieldResumeEffect(trans).visit_place(
+            &resume_place,
+            PlaceContext::MutatingUse(MutatingUseContext::Yield),
+            Location::START,
+        )
     }
 }
 
@@ -98,28 +94,51 @@ where
     T: GenKill<Local>,
 {
     fn visit_place(&mut self, place: &mir::Place<'tcx>, context: PlaceContext, location: Location) {
-        let local = place.local;
-
-        // We purposefully do not call `super_place` here to avoid calling `visit_local` for this
-        // place with one of the `Projection` variants of `PlaceContext`.
-        self.visit_projection(place.as_ref(), context, location);
+        if let PlaceContext::MutatingUse(MutatingUseContext::Yield) = context {
+            // The resume place is evaluated and assigned to only after generator resumes, so its
+            // effect is handled separately in `yield_resume_effect`.
+            return;
+        }
 
         match DefUse::for_place(*place, context) {
-            Some(DefUse::Def) => self.0.kill(local),
-            Some(DefUse::Use) => self.0.gen(local),
+            Some(DefUse::Def) => {
+                if let PlaceContext::MutatingUse(
+                    MutatingUseContext::Call | MutatingUseContext::AsmOutput,
+                ) = context
+                {
+                    // For the associated terminators, this is only a `Def` when the terminator returns
+                    // "successfully." As such, we handle this case separately in `call_return_effect`
+                    // above. However, if the place looks like `*_5`, this is still unconditionally a use of
+                    // `_5`.
+                } else {
+                    self.0.kill(place.local);
+                }
+            }
+            Some(DefUse::Use) => self.0.gen(place.local),
             None => {}
         }
+
+        self.visit_projection(place.as_ref(), context, location);
     }
 
     fn visit_local(&mut self, local: Local, context: PlaceContext, _: Location) {
-        // Because we do not call `super_place` above, `visit_local` is only called for locals that
-        // do not appear as part of  a `Place` in the MIR. This handles cases like the implicit use
-        // of the return place in a `Return` terminator or the index in an `Index` projection.
-        match DefUse::for_place(local.into(), context) {
-            Some(DefUse::Def) => self.0.kill(local),
-            Some(DefUse::Use) => self.0.gen(local),
-            None => {}
-        }
+        DefUse::apply(self.0, local.into(), context);
+    }
+}
+
+struct YieldResumeEffect<'a, T>(&'a mut T);
+
+impl<'tcx, T> Visitor<'tcx> for YieldResumeEffect<'_, T>
+where
+    T: GenKill<Local>,
+{
+    fn visit_place(&mut self, place: &mir::Place<'tcx>, context: PlaceContext, location: Location) {
+        DefUse::apply(self.0, *place, context);
+        self.visit_projection(place.as_ref(), context, location);
+    }
+
+    fn visit_local(&mut self, local: Local, context: PlaceContext, _: Location) {
+        DefUse::apply(self.0, local.into(), context);
     }
 }
 
@@ -130,11 +149,25 @@ enum DefUse {
 }
 
 impl DefUse {
+    fn apply<'tcx>(trans: &mut impl GenKill<Local>, place: Place<'tcx>, context: PlaceContext) {
+        match DefUse::for_place(place, context) {
+            Some(DefUse::Def) => trans.kill(place.local),
+            Some(DefUse::Use) => trans.gen(place.local),
+            None => {}
+        }
+    }
+
     fn for_place<'tcx>(place: Place<'tcx>, context: PlaceContext) -> Option<DefUse> {
         match context {
             PlaceContext::NonUse(_) => None,
 
-            PlaceContext::MutatingUse(MutatingUseContext::Store | MutatingUseContext::Deinit) => {
+            PlaceContext::MutatingUse(
+                MutatingUseContext::Call
+                | MutatingUseContext::Yield
+                | MutatingUseContext::AsmOutput
+                | MutatingUseContext::Store
+                | MutatingUseContext::Deinit,
+            ) => {
                 if place.is_indirect() {
                     // Treat derefs as a use of the base local. `*p = 4` is not a def of `p` but a
                     // use.
@@ -152,16 +185,6 @@ impl DefUse {
                 place.is_indirect().then_some(DefUse::Use)
             }
 
-            // For the associated terminators, this is only a `Def` when the terminator returns
-            // "successfully." As such, we handle this case separately in `call_return_effect`
-            // above. However, if the place looks like `*_5`, this is still unconditionally a use of
-            // `_5`.
-            PlaceContext::MutatingUse(
-                MutatingUseContext::Call
-                | MutatingUseContext::Yield
-                | MutatingUseContext::AsmOutput,
-            ) => place.is_indirect().then_some(DefUse::Use),
-
             // All other contexts are uses...
             PlaceContext::MutatingUse(
                 MutatingUseContext::AddressOf
@@ -290,8 +313,10 @@ impl<'a, 'tcx> Analysis<'tcx> for MaybeTransitiveLiveLocals<'a> {
         _resume_block: mir::BasicBlock,
         resume_place: mir::Place<'tcx>,
     ) {
-        if let Some(local) = resume_place.as_local() {
-            trans.remove(local);
-        }
+        YieldResumeEffect(trans).visit_place(
+            &resume_place,
+            PlaceContext::MutatingUse(MutatingUseContext::Yield),
+            Location::START,
+        )
     }
 }
diff --git a/compiler/rustc_mir_transform/src/elaborate_box_derefs.rs b/compiler/rustc_mir_transform/src/elaborate_box_derefs.rs
index e04094153df..294af2455d0 100644
--- a/compiler/rustc_mir_transform/src/elaborate_box_derefs.rs
+++ b/compiler/rustc_mir_transform/src/elaborate_box_derefs.rs
@@ -107,27 +107,8 @@ impl<'tcx> MirPass<'tcx> for ElaborateBoxDerefs {
             let mut visitor =
                 ElaborateBoxDerefVisitor { tcx, unique_did, nonnull_did, local_decls, patch };
 
-            for (block, BasicBlockData { statements, terminator, .. }) in
-                body.basic_blocks.as_mut_preserves_cfg().iter_enumerated_mut()
-            {
-                let mut index = 0;
-                for statement in statements {
-                    let location = Location { block, statement_index: index };
-                    visitor.visit_statement(statement, location);
-                    index += 1;
-                }
-
-                let location = Location { block, statement_index: index };
-                match terminator {
-                    // yielding into a box is handled when lowering generators
-                    Some(Terminator { kind: TerminatorKind::Yield { value, .. }, .. }) => {
-                        visitor.visit_operand(value, location);
-                    }
-                    Some(terminator) => {
-                        visitor.visit_terminator(terminator, location);
-                    }
-                    None => {}
-                }
+            for (block, data) in body.basic_blocks.as_mut_preserves_cfg().iter_enumerated_mut() {
+                visitor.visit_basic_block_data(block, data);
             }
 
             visitor.patch.apply(body);
diff --git a/compiler/rustc_mir_transform/src/generator.rs b/compiler/rustc_mir_transform/src/generator.rs
index 91ecf387922..5b0d9900c0f 100644
--- a/compiler/rustc_mir_transform/src/generator.rs
+++ b/compiler/rustc_mir_transform/src/generator.rs
@@ -1182,8 +1182,6 @@ fn create_cases<'tcx>(
     transform: &TransformVisitor<'tcx>,
     operation: Operation,
 ) -> Vec<(usize, BasicBlock)> {
-    let tcx = transform.tcx;
-
     let source_info = SourceInfo::outermost(body.span);
 
     transform
@@ -1216,85 +1214,13 @@ fn create_cases<'tcx>(
                 if operation == Operation::Resume {
                     // Move the resume argument to the destination place of the `Yield` terminator
                     let resume_arg = Local::new(2); // 0 = return, 1 = self
-
-                    // handle `box yield` properly
-                    let box_place = if let [projection @ .., ProjectionElem::Deref] =
-                        &**point.resume_arg.projection
-                    {
-                        let box_place =
-                            Place::from(point.resume_arg.local).project_deeper(projection, tcx);
-
-                        let box_ty = box_place.ty(&body.local_decls, tcx).ty;
-
-                        if box_ty.is_box() { Some((box_place, box_ty)) } else { None }
-                    } else {
-                        None
-                    };
-
-                    if let Some((box_place, box_ty)) = box_place {
-                        let unique_did = box_ty
-                            .ty_adt_def()
-                            .expect("expected Box to be an Adt")
-                            .non_enum_variant()
-                            .fields[0]
-                            .did;
-
-                        let Some(nonnull_def) = tcx.type_of(unique_did).ty_adt_def() else {
-                            span_bug!(tcx.def_span(unique_did), "expected Box to contain Unique")
-                        };
-
-                        let nonnull_did = nonnull_def.non_enum_variant().fields[0].did;
-
-                        let (unique_ty, nonnull_ty, ptr_ty) =
-                            crate::elaborate_box_derefs::build_ptr_tys(
-                                tcx,
-                                box_ty.boxed_ty(),
-                                unique_did,
-                                nonnull_did,
-                            );
-
-                        let ptr_local = body.local_decls.push(LocalDecl::new(ptr_ty, body.span));
-
-                        statements.push(Statement {
-                            source_info,
-                            kind: StatementKind::StorageLive(ptr_local),
-                        });
-
-                        statements.push(Statement {
-                            source_info,
-                            kind: StatementKind::Assign(Box::new((
-                                Place::from(ptr_local),
-                                Rvalue::Use(Operand::Copy(box_place.project_deeper(
-                                    &crate::elaborate_box_derefs::build_projection(
-                                        unique_ty, nonnull_ty, ptr_ty,
-                                    ),
-                                    tcx,
-                                ))),
-                            ))),
-                        });
-
-                        statements.push(Statement {
-                            source_info,
-                            kind: StatementKind::Assign(Box::new((
-                                Place::from(ptr_local)
-                                    .project_deeper(&[ProjectionElem::Deref], tcx),
-                                Rvalue::Use(Operand::Move(resume_arg.into())),
-                            ))),
-                        });
-
-                        statements.push(Statement {
-                            source_info,
-                            kind: StatementKind::StorageDead(ptr_local),
-                        });
-                    } else {
-                        statements.push(Statement {
-                            source_info,
-                            kind: StatementKind::Assign(Box::new((
-                                point.resume_arg,
-                                Rvalue::Use(Operand::Move(resume_arg.into())),
-                            ))),
-                        });
-                    }
+                    statements.push(Statement {
+                        source_info,
+                        kind: StatementKind::Assign(Box::new((
+                            point.resume_arg,
+                            Rvalue::Use(Operand::Move(resume_arg.into())),
+                        ))),
+                    });
                 }
 
                 // Then jump to the real target
diff --git a/compiler/rustc_serialize/src/lib.rs b/compiler/rustc_serialize/src/lib.rs
index 079d44bac68..91f4cfaf5ac 100644
--- a/compiler/rustc_serialize/src/lib.rs
+++ b/compiler/rustc_serialize/src/lib.rs
@@ -16,6 +16,7 @@ Core encoding and decoding interfaces.
 #![feature(maybe_uninit_slice)]
 #![feature(let_else)]
 #![feature(new_uninit)]
+#![feature(allocator_api)]
 #![cfg_attr(test, feature(test))]
 #![allow(rustc::internal)]
 #![deny(rustc::untranslatable_diagnostic)]
diff --git a/compiler/rustc_serialize/src/serialize.rs b/compiler/rustc_serialize/src/serialize.rs
index 9bd5550038f..751b209f11a 100644
--- a/compiler/rustc_serialize/src/serialize.rs
+++ b/compiler/rustc_serialize/src/serialize.rs
@@ -4,6 +4,7 @@
 Core encoding and decoding interfaces.
 */
 
+use std::alloc::Allocator;
 use std::borrow::Cow;
 use std::cell::{Cell, RefCell};
 use std::marker::PhantomData;
@@ -229,9 +230,9 @@ impl<D: Decoder, T> Decodable<D> for PhantomData<T> {
     }
 }
 
-impl<D: Decoder, T: Decodable<D>> Decodable<D> for Box<[T]> {
-    fn decode(d: &mut D) -> Box<[T]> {
-        let v: Vec<T> = Decodable::decode(d);
+impl<D: Decoder, A: Allocator + Default, T: Decodable<D>> Decodable<D> for Box<[T], A> {
+    fn decode(d: &mut D) -> Box<[T], A> {
+        let v: Vec<T, A> = Decodable::decode(d);
         v.into_boxed_slice()
     }
 }
@@ -264,12 +265,13 @@ impl<S: Encoder, T: Encodable<S>> Encodable<S> for Vec<T> {
     }
 }
 
-impl<D: Decoder, T: Decodable<D>> Decodable<D> for Vec<T> {
-    default fn decode(d: &mut D) -> Vec<T> {
+impl<D: Decoder, T: Decodable<D>, A: Allocator + Default> Decodable<D> for Vec<T, A> {
+    default fn decode(d: &mut D) -> Vec<T, A> {
         let len = d.read_usize();
+        let allocator = A::default();
         // SAFETY: we set the capacity in advance, only write elements, and
         // only set the length at the end once the writing has succeeded.
-        let mut vec = Vec::with_capacity(len);
+        let mut vec = Vec::with_capacity_in(len, allocator);
         unsafe {
             let ptr: *mut T = vec.as_mut_ptr();
             for i in 0..len {
@@ -457,13 +459,15 @@ impl<D: Decoder, T: Decodable<D>> Decodable<D> for Arc<T> {
     }
 }
 
-impl<S: Encoder, T: ?Sized + Encodable<S>> Encodable<S> for Box<T> {
+impl<S: Encoder, T: ?Sized + Encodable<S>, A: Allocator + Default> Encodable<S> for Box<T, A> {
     fn encode(&self, s: &mut S) {
-        (**self).encode(s);
+        (**self).encode(s)
     }
 }
-impl<D: Decoder, T: Decodable<D>> Decodable<D> for Box<T> {
-    fn decode(d: &mut D) -> Box<T> {
-        Box::new(Decodable::decode(d))
+
+impl<D: Decoder, A: Allocator + Default, T: Decodable<D>> Decodable<D> for Box<T, A> {
+    fn decode(d: &mut D) -> Box<T, A> {
+        let allocator = A::default();
+        Box::new_in(Decodable::decode(d), allocator)
     }
 }
diff --git a/compiler/rustc_transmute/src/layout/tree.rs b/compiler/rustc_transmute/src/layout/tree.rs
index 70b3ba02b05..93cab7ca533 100644
--- a/compiler/rustc_transmute/src/layout/tree.rs
+++ b/compiler/rustc_transmute/src/layout/tree.rs
@@ -1,4 +1,5 @@
 use super::{Byte, Def, Ref};
+use std::ops::ControlFlow;
 
 #[cfg(test)]
 mod tests;
@@ -86,17 +87,18 @@ where
         F: Fn(D) -> bool,
     {
         match self {
-            Self::Seq(elts) => elts
-                .into_iter()
-                .map(|elt| elt.prune(f))
-                .try_fold(Tree::unit(), |elts, elt| {
+            Self::Seq(elts) => match elts.into_iter().map(|elt| elt.prune(f)).try_fold(
+                Tree::unit(),
+                |elts, elt| {
                     if elt == Tree::uninhabited() {
-                        Err(Tree::uninhabited())
+                        ControlFlow::Break(Tree::uninhabited())
                     } else {
-                        Ok(elts.then(elt))
+                        ControlFlow::Continue(elts.then(elt))
                     }
-                })
-                .into_ok_or_err(),
+                },
+            ) {
+                ControlFlow::Break(node) | ControlFlow::Continue(node) => node,
+            },
             Self::Alt(alts) => alts
                 .into_iter()
                 .map(|alt| alt.prune(f))
diff --git a/compiler/rustc_transmute/src/lib.rs b/compiler/rustc_transmute/src/lib.rs
index 32e6cb9c64f..89b1ce5abe9 100644
--- a/compiler/rustc_transmute/src/lib.rs
+++ b/compiler/rustc_transmute/src/lib.rs
@@ -1,11 +1,4 @@
-#![feature(
-    alloc_layout_extra,
-    control_flow_enum,
-    decl_macro,
-    iterator_try_reduce,
-    never_type,
-    result_into_ok_or_err
-)]
+#![feature(alloc_layout_extra, control_flow_enum, decl_macro, iterator_try_reduce, never_type)]
 #![allow(dead_code, unused_variables)]
 #![deny(rustc::untranslatable_diagnostic)]
 #![deny(rustc::diagnostic_outside_of_impl)]
diff --git a/compiler/rustc_typeck/src/check/method/suggest.rs b/compiler/rustc_typeck/src/check/method/suggest.rs
index 44c7c148c75..441a62256de 100644
--- a/compiler/rustc_typeck/src/check/method/suggest.rs
+++ b/compiler/rustc_typeck/src/check/method/suggest.rs
@@ -1066,16 +1066,29 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     // that had unsatisfied trait bounds
                     if unsatisfied_predicates.is_empty() {
                         let def_kind = lev_candidate.kind.as_def_kind();
-                        err.span_suggestion(
-                            span,
-                            &format!(
-                                "there is {} {} with a similar name",
-                                def_kind.article(),
-                                def_kind.descr(lev_candidate.def_id),
-                            ),
-                            lev_candidate.name,
-                            Applicability::MaybeIncorrect,
-                        );
+                        // Methods are defined within the context of a struct and their first parameter is always self,
+                        // which represents the instance of the struct the method is being called on
+                        // Associated functions don’t take self as a parameter and
+                        // they are not methods because they don’t have an instance of the struct to work with.
+                        if def_kind == DefKind::AssocFn && lev_candidate.fn_has_self_parameter {
+                            err.span_suggestion(
+                                span,
+                                &format!("there is a method with a similar name",),
+                                lev_candidate.name,
+                                Applicability::MaybeIncorrect,
+                            );
+                        } else {
+                            err.span_suggestion(
+                                span,
+                                &format!(
+                                    "there is {} {} with a similar name",
+                                    def_kind.article(),
+                                    def_kind.descr(lev_candidate.def_id),
+                                ),
+                                lev_candidate.name,
+                                Applicability::MaybeIncorrect,
+                            );
+                        }
                     }
                 }
 
diff --git a/library/core/src/lib.rs b/library/core/src/lib.rs
index 8d04a213f50..afec497ee44 100644
--- a/library/core/src/lib.rs
+++ b/library/core/src/lib.rs
@@ -149,6 +149,7 @@
 #![feature(maybe_uninit_uninit_array)]
 #![feature(ptr_metadata)]
 #![feature(slice_ptr_get)]
+#![feature(slice_split_at_unchecked)]
 #![feature(str_internals)]
 #![feature(utf16_extra)]
 #![feature(utf16_extra_const)]
diff --git a/library/core/src/panicking.rs b/library/core/src/panicking.rs
index 7a575a88e52..d4afe0f5326 100644
--- a/library/core/src/panicking.rs
+++ b/library/core/src/panicking.rs
@@ -190,11 +190,11 @@ pub fn assert_matches_failed<T: fmt::Debug + ?Sized>(
     right: &str,
     args: Option<fmt::Arguments<'_>>,
 ) -> ! {
-    // Use the Display implementation to display the pattern.
+    // The pattern is a string so it can be displayed directly.
     struct Pattern<'a>(&'a str);
     impl fmt::Debug for Pattern<'_> {
         fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-            fmt::Display::fmt(self.0, f)
+            f.write_str(self.0)
         }
     }
     assert_failed_inner(AssertKind::Match, &left, &Pattern(right), args);
diff --git a/library/core/src/result.rs b/library/core/src/result.rs
index 75dcb4cdba9..76eaa191f78 100644
--- a/library/core/src/result.rs
+++ b/library/core/src/result.rs
@@ -1776,40 +1776,6 @@ impl<T, E> Result<Result<T, E>, E> {
     }
 }
 
-impl<T> Result<T, T> {
-    /// Returns the [`Ok`] value if `self` is `Ok`, and the [`Err`] value if
-    /// `self` is `Err`.
-    ///
-    /// In other words, this function returns the value (the `T`) of a
-    /// `Result<T, T>`, regardless of whether or not that result is `Ok` or
-    /// `Err`.
-    ///
-    /// This can be useful in conjunction with APIs such as
-    /// [`Atomic*::compare_exchange`], or [`slice::binary_search`], but only in
-    /// cases where you don't care if the result was `Ok` or not.
-    ///
-    /// [`Atomic*::compare_exchange`]: crate::sync::atomic::AtomicBool::compare_exchange
-    ///
-    /// # Examples
-    ///
-    /// ```
-    /// #![feature(result_into_ok_or_err)]
-    /// let ok: Result<u32, u32> = Ok(3);
-    /// let err: Result<u32, u32> = Err(4);
-    ///
-    /// assert_eq!(ok.into_ok_or_err(), 3);
-    /// assert_eq!(err.into_ok_or_err(), 4);
-    /// ```
-    #[inline]
-    #[unstable(feature = "result_into_ok_or_err", reason = "newly added", issue = "82223")]
-    pub const fn into_ok_or_err(self) -> T {
-        match self {
-            Ok(v) => v,
-            Err(v) => v,
-        }
-    }
-}
-
 // This is a separate function to reduce the code size of the methods
 #[cfg(not(feature = "panic_immediate_abort"))]
 #[inline(never)]
diff --git a/library/core/src/slice/mod.rs b/library/core/src/slice/mod.rs
index ea6a70c2f4e..38f05f471cd 100644
--- a/library/core/src/slice/mod.rs
+++ b/library/core/src/slice/mod.rs
@@ -1541,13 +1541,14 @@ impl<T> [T] {
     /// }
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
+    #[rustc_const_unstable(feature = "const_slice_split_at_not_mut", issue = "none")]
     #[inline]
     #[track_caller]
     #[must_use]
-    pub fn split_at(&self, mid: usize) -> (&[T], &[T]) {
+    pub const fn split_at(&self, mid: usize) -> (&[T], &[T]) {
         assert!(mid <= self.len());
         // SAFETY: `[ptr; mid]` and `[mid; len]` are inside `self`, which
-        // fulfills the requirements of `from_raw_parts_mut`.
+        // fulfills the requirements of `split_at_unchecked`.
         unsafe { self.split_at_unchecked(mid) }
     }
 
@@ -1626,11 +1627,19 @@ impl<T> [T] {
     /// }
     /// ```
     #[unstable(feature = "slice_split_at_unchecked", reason = "new API", issue = "76014")]
+    #[rustc_const_unstable(feature = "slice_split_at_unchecked", issue = "76014")]
     #[inline]
     #[must_use]
-    pub unsafe fn split_at_unchecked(&self, mid: usize) -> (&[T], &[T]) {
+    pub const unsafe fn split_at_unchecked(&self, mid: usize) -> (&[T], &[T]) {
+        // HACK: the const function `from_raw_parts` is used to make this
+        // function const; previously the implementation used
+        // `(self.get_unchecked(..mid), self.get_unchecked(mid..))`
+
+        let len = self.len();
+        let ptr = self.as_ptr();
+
         // SAFETY: Caller has to check that `0 <= mid <= self.len()`
-        unsafe { (self.get_unchecked(..mid), self.get_unchecked(mid..)) }
+        unsafe { (from_raw_parts(ptr, mid), from_raw_parts(ptr.add(mid), len - mid)) }
     }
 
     /// Divides one mutable slice into two at an index, without doing bounds checking.
diff --git a/library/core/tests/lib.rs b/library/core/tests/lib.rs
index 59510d3cc2a..c315f3a7975 100644
--- a/library/core/tests/lib.rs
+++ b/library/core/tests/lib.rs
@@ -75,7 +75,6 @@
 #![feature(const_pin)]
 #![feature(never_type)]
 #![feature(unwrap_infallible)]
-#![feature(result_into_ok_or_err)]
 #![feature(pointer_byte_offsets)]
 #![feature(portable_simd)]
 #![feature(ptr_metadata)]
diff --git a/library/core/tests/result.rs b/library/core/tests/result.rs
index 103e8cc3a96..50926da3ce7 100644
--- a/library/core/tests/result.rs
+++ b/library/core/tests/result.rs
@@ -96,15 +96,6 @@ fn test_unwrap_or() {
 }
 
 #[test]
-fn test_ok_or_err() {
-    let ok: Result<isize, isize> = Ok(100);
-    let err: Result<isize, isize> = Err(200);
-
-    assert_eq!(ok.into_ok_or_err(), 100);
-    assert_eq!(err.into_ok_or_err(), 200);
-}
-
-#[test]
 fn test_unwrap_or_else() {
     fn handler(msg: &'static str) -> isize {
         if msg == "I got this." { 50 } else { panic!("BadBad") }
diff --git a/src/librustdoc/html/static/css/rustdoc.css b/src/librustdoc/html/static/css/rustdoc.css
index f1cd3defbef..f6a7875fddc 100644
--- a/src/librustdoc/html/static/css/rustdoc.css
+++ b/src/librustdoc/html/static/css/rustdoc.css
@@ -750,16 +750,6 @@ pre, .rustdoc.source .example-wrap {
 	padding: 0;
 }
 
-.content .multi-column {
-	-moz-column-count: 5;
-	-moz-column-gap: 2.5em;
-	-webkit-column-count: 5;
-	-webkit-column-gap: 2.5em;
-	column-count: 5;
-	column-gap: 2.5em;
-}
-.content .multi-column li { width: 100%; display: inline-block; }
-
 .content > .methods > .method {
 	font-size: 1rem;
 	position: relative;
diff --git a/src/test/ui/auto-ref-slice-plus-ref.stderr b/src/test/ui/auto-ref-slice-plus-ref.stderr
index eb8447ff0f3..e2883050720 100644
--- a/src/test/ui/auto-ref-slice-plus-ref.stderr
+++ b/src/test/ui/auto-ref-slice-plus-ref.stderr
@@ -2,7 +2,7 @@ error[E0599]: no method named `test_mut` found for struct `Vec<{integer}>` in th
   --> $DIR/auto-ref-slice-plus-ref.rs:7:7
    |
 LL |     a.test_mut();
-   |       ^^^^^^^^ help: there is an associated function with a similar name: `get_mut`
+   |       ^^^^^^^^ help: there is a method with a similar name: `get_mut`
    |
    = help: items from traits can only be used if the trait is implemented and in scope
 note: `MyIter` defines an item `test_mut`, perhaps you need to implement it
diff --git a/src/test/ui/block-result/issue-3563.stderr b/src/test/ui/block-result/issue-3563.stderr
index 5255e48bee1..be551f6e889 100644
--- a/src/test/ui/block-result/issue-3563.stderr
+++ b/src/test/ui/block-result/issue-3563.stderr
@@ -2,7 +2,7 @@ error[E0599]: no method named `b` found for reference `&Self` in the current sco
   --> $DIR/issue-3563.rs:3:17
    |
 LL |         || self.b()
-   |                 ^ help: there is an associated function with a similar name: `a`
+   |                 ^ help: there is a method with a similar name: `a`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/issues/issue-28344.stderr b/src/test/ui/issues/issue-28344.stderr
index b1d1c01b27a..85a8698afc5 100644
--- a/src/test/ui/issues/issue-28344.stderr
+++ b/src/test/ui/issues/issue-28344.stderr
@@ -25,7 +25,7 @@ LL |     let x: u8 = BitXor::bitor(0 as u8, 0 as u8);
    |                         ^^^^^
    |                         |
    |                         function or associated item not found in `dyn BitXor<_>`
-   |                         help: there is an associated function with a similar name: `bitxor`
+   |                         help: there is a method with a similar name: `bitxor`
 
 warning: trait objects without an explicit `dyn` are deprecated
   --> $DIR/issue-28344.rs:10:13
@@ -53,7 +53,7 @@ LL |     let g = BitXor::bitor;
    |                     ^^^^^
    |                     |
    |                     function or associated item not found in `dyn BitXor<_>`
-   |                     help: there is an associated function with a similar name: `bitxor`
+   |                     help: there is a method with a similar name: `bitxor`
 
 error: aborting due to 4 previous errors; 2 warnings emitted
 
diff --git a/src/test/ui/suggestions/dont-suggest-pin-array-dot-set.stderr b/src/test/ui/suggestions/dont-suggest-pin-array-dot-set.stderr
index 677aa031bf7..c66da3ea6d9 100644
--- a/src/test/ui/suggestions/dont-suggest-pin-array-dot-set.stderr
+++ b/src/test/ui/suggestions/dont-suggest-pin-array-dot-set.stderr
@@ -2,7 +2,7 @@ error[E0599]: no method named `set` found for array `[u8; 1]` in the current sco
   --> $DIR/dont-suggest-pin-array-dot-set.rs:14:7
    |
 LL |     a.set(0, 3);
-   |       ^^^ help: there is an associated function with a similar name: `get`
+   |       ^^^ help: there is a method with a similar name: `get`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/suggestions/suggest-methods.stderr b/src/test/ui/suggestions/suggest-methods.stderr
index 97d7e6696a8..03cb9c77922 100644
--- a/src/test/ui/suggestions/suggest-methods.stderr
+++ b/src/test/ui/suggestions/suggest-methods.stderr
@@ -5,25 +5,25 @@ LL | struct Foo;
    | ---------- method `bat` not found for this struct
 ...
 LL |     f.bat(1.0);
-   |       ^^^ help: there is an associated function with a similar name: `bar`
+   |       ^^^ help: there is a method with a similar name: `bar`
 
 error[E0599]: no method named `is_emtpy` found for struct `String` in the current scope
   --> $DIR/suggest-methods.rs:21:15
    |
 LL |     let _ = s.is_emtpy();
-   |               ^^^^^^^^ help: there is an associated function with a similar name: `is_empty`
+   |               ^^^^^^^^ help: there is a method with a similar name: `is_empty`
 
 error[E0599]: no method named `count_eos` found for type `u32` in the current scope
   --> $DIR/suggest-methods.rs:25:19
    |
 LL |     let _ = 63u32.count_eos();
-   |                   ^^^^^^^^^ help: there is an associated function with a similar name: `count_zeros`
+   |                   ^^^^^^^^^ help: there is a method with a similar name: `count_zeros`
 
 error[E0599]: no method named `count_o` found for type `u32` in the current scope
   --> $DIR/suggest-methods.rs:28:19
    |
 LL |     let _ = 63u32.count_o();
-   |                   ^^^^^^^ help: there is an associated function with a similar name: `count_ones`
+   |                   ^^^^^^^ help: there is a method with a similar name: `count_ones`
 
 error: aborting due to 4 previous errors
 
diff --git a/src/test/ui/traits/trait-upcasting/subtrait-method.stderr b/src/test/ui/traits/trait-upcasting/subtrait-method.stderr
index 8c69011800b..af7a410f6d9 100644
--- a/src/test/ui/traits/trait-upcasting/subtrait-method.stderr
+++ b/src/test/ui/traits/trait-upcasting/subtrait-method.stderr
@@ -2,7 +2,7 @@ error[E0599]: no method named `c` found for reference `&dyn Bar` in the current
   --> $DIR/subtrait-method.rs:56:9
    |
 LL |     bar.c();
-   |         ^ help: there is an associated function with a similar name: `a`
+   |         ^ help: there is a method with a similar name: `a`
    |
    = help: items from traits can only be used if the trait is implemented and in scope
 note: `Baz` defines an item `c`, perhaps you need to implement it
@@ -15,7 +15,7 @@ error[E0599]: no method named `b` found for reference `&dyn Foo` in the current
   --> $DIR/subtrait-method.rs:60:9
    |
 LL |     foo.b();
-   |         ^ help: there is an associated function with a similar name: `a`
+   |         ^ help: there is a method with a similar name: `a`
    |
    = help: items from traits can only be used if the trait is implemented and in scope
 note: `Bar` defines an item `b`, perhaps you need to implement it
@@ -28,7 +28,7 @@ error[E0599]: no method named `c` found for reference `&dyn Foo` in the current
   --> $DIR/subtrait-method.rs:62:9
    |
 LL |     foo.c();
-   |         ^ help: there is an associated function with a similar name: `a`
+   |         ^ help: there is a method with a similar name: `a`
    |
    = help: items from traits can only be used if the trait is implemented and in scope
 note: `Baz` defines an item `c`, perhaps you need to implement it
@@ -41,7 +41,7 @@ error[E0599]: no method named `b` found for reference `&dyn Foo` in the current
   --> $DIR/subtrait-method.rs:66:9
    |
 LL |     foo.b();
-   |         ^ help: there is an associated function with a similar name: `a`
+   |         ^ help: there is a method with a similar name: `a`
    |
    = help: items from traits can only be used if the trait is implemented and in scope
 note: `Bar` defines an item `b`, perhaps you need to implement it
@@ -54,7 +54,7 @@ error[E0599]: no method named `c` found for reference `&dyn Foo` in the current
   --> $DIR/subtrait-method.rs:68:9
    |
 LL |     foo.c();
-   |         ^ help: there is an associated function with a similar name: `a`
+   |         ^ help: there is a method with a similar name: `a`
    |
    = help: items from traits can only be used if the trait is implemented and in scope
 note: `Baz` defines an item `c`, perhaps you need to implement it
diff --git a/src/test/ui/unpretty/bad-literal.rs b/src/test/ui/unpretty/bad-literal.rs
new file mode 100644
index 00000000000..6dcc0da30cc
--- /dev/null
+++ b/src/test/ui/unpretty/bad-literal.rs
@@ -0,0 +1,8 @@
+// compile-flags: -Zunpretty=hir
+// check-fail
+
+// In #100948 this caused an ICE with -Zunpretty=hir.
+fn main() {
+    1u;
+    //~^ ERROR invalid suffix `u` for number literal
+}
diff --git a/src/test/ui/unpretty/bad-literal.stderr b/src/test/ui/unpretty/bad-literal.stderr
new file mode 100644
index 00000000000..f3fcb4a4e92
--- /dev/null
+++ b/src/test/ui/unpretty/bad-literal.stderr
@@ -0,0 +1,10 @@
+error: invalid suffix `u` for number literal
+  --> $DIR/bad-literal.rs:6:5
+   |
+LL |     1u;
+   |     ^^ invalid suffix `u`
+   |
+   = help: the suffix must be one of the numeric types (`u32`, `isize`, `f32`, etc.)
+
+error: aborting due to previous error
+
diff --git a/src/test/ui/unpretty/bad-literal.stdout b/src/test/ui/unpretty/bad-literal.stdout
new file mode 100644
index 00000000000..8df93327033
--- /dev/null
+++ b/src/test/ui/unpretty/bad-literal.stdout
@@ -0,0 +1,11 @@
+#[prelude_import]
+use ::std::prelude::rust_2015::*;
+#[macro_use]
+extern crate std;
+// compile-flags: -Zunpretty=hir
+// check-fail
+
+// In #100948 this caused an ICE with -Zunpretty=hir.
+fn main() {
+        <bad-literal>;
+    }