Auto merge of #70062 - Centril:rollup-synwle8, r=Centril

Rollup of 7 pull requests

Successful merges:

 - #69811 (resolve: Print import chains on privacy errors)
 - #69870 (expand: Implement something similar to `#[cfg(accessible(path))]`)
 - #69881 (VariantSizeDifferences: bail on SizeOverflow)
 - #70000 (resolve: Fix regression in resolution of raw keywords in paths)
 - #70029 (Bump the bootstrap compiler)
 - #70046 (Use sublice patterns to avoid computing the len)
 - #70049 (Fiddle `ParamEnv` through to a place that used to use `ParamEnv::empty` in a buggy manner)

Failed merges:

r? @ghost

5 files changed, 25 insertions, 31 deletions

diff --git a/src/libcore/cell.rs b/src/libcore/cell.rs
index dbf073cd479..a922d4f118b 100644
--- a/src/libcore/cell.rs
+++ b/src/libcore/cell.rs
@@ -1569,7 +1569,7 @@ impl<T: ?Sized + fmt::Display> fmt::Display for RefMut<'_, T> {
 #[lang = "unsafe_cell"]
 #[stable(feature = "rust1", since = "1.0.0")]
 #[repr(transparent)]
-#[cfg_attr(not(bootstrap), repr(no_niche))] // rust-lang/rust#68303.
+#[repr(no_niche)] // rust-lang/rust#68303.
 pub struct UnsafeCell<T: ?Sized> {
     value: T,
 }
diff --git a/src/libcore/lib.rs b/src/libcore/lib.rs
index a1dde1d51ef..5a731766054 100644
--- a/src/libcore/lib.rs
+++ b/src/libcore/lib.rs
@@ -140,7 +140,7 @@
 #![feature(associated_type_bounds)]
 #![feature(const_type_id)]
 #![feature(const_caller_location)]
-#![cfg_attr(not(bootstrap), feature(no_niche))] // rust-lang/rust#68303
+#![feature(no_niche)] // rust-lang/rust#68303
 
 #[prelude_import]
 #[allow(unused)]
diff --git a/src/libcore/macros/mod.rs b/src/libcore/macros/mod.rs
index 04af5b5f768..a0873fe6b62 100644
--- a/src/libcore/macros/mod.rs
+++ b/src/libcore/macros/mod.rs
@@ -1404,6 +1404,18 @@ pub(crate) mod builtin {
         /* compiler built-in */
     }
 
+    /// Keeps the item it's applied to if the passed path is accessible, and removes it otherwise.
+    #[cfg(not(bootstrap))]
+    #[unstable(
+        feature = "cfg_accessible",
+        issue = "64797",
+        reason = "`cfg_accessible` is not fully implemented"
+    )]
+    #[rustc_builtin_macro]
+    pub macro cfg_accessible($item:item) {
+        /* compiler built-in */
+    }
+
     /// Unstable implementation detail of the `rustc` compiler, do not use.
     #[rustc_builtin_macro]
     #[stable(feature = "rust1", since = "1.0.0")]
diff --git a/src/libcore/ops/generator.rs b/src/libcore/ops/generator.rs
index 4e43561996c..4f23620b92b 100644
--- a/src/libcore/ops/generator.rs
+++ b/src/libcore/ops/generator.rs
@@ -67,7 +67,7 @@ pub enum GeneratorState<Y, R> {
 #[lang = "generator"]
 #[unstable(feature = "generator_trait", issue = "43122")]
 #[fundamental]
-pub trait Generator<#[cfg(not(bootstrap))] R = ()> {
+pub trait Generator<R = ()> {
     /// The type of value this generator yields.
     ///
     /// This associated type corresponds to the `yield` expression and the
@@ -110,35 +110,9 @@ pub trait Generator<#[cfg(not(bootstrap))] R = ()> {
     /// been returned previously. While generator literals in the language are
     /// guaranteed to panic on resuming after `Complete`, this is not guaranteed
     /// for all implementations of the `Generator` trait.
-    fn resume(
-        self: Pin<&mut Self>,
-        #[cfg(not(bootstrap))] arg: R,
-    ) -> GeneratorState<Self::Yield, Self::Return>;
+    fn resume(self: Pin<&mut Self>, arg: R) -> GeneratorState<Self::Yield, Self::Return>;
 }
 
-#[cfg(bootstrap)]
-#[unstable(feature = "generator_trait", issue = "43122")]
-impl<G: ?Sized + Generator> Generator for Pin<&mut G> {
-    type Yield = G::Yield;
-    type Return = G::Return;
-
-    fn resume(mut self: Pin<&mut Self>) -> GeneratorState<Self::Yield, Self::Return> {
-        G::resume((*self).as_mut())
-    }
-}
-
-#[cfg(bootstrap)]
-#[unstable(feature = "generator_trait", issue = "43122")]
-impl<G: ?Sized + Generator + Unpin> Generator for &mut G {
-    type Yield = G::Yield;
-    type Return = G::Return;
-
-    fn resume(mut self: Pin<&mut Self>) -> GeneratorState<Self::Yield, Self::Return> {
-        G::resume(Pin::new(&mut *self))
-    }
-}
-
-#[cfg(not(bootstrap))]
 #[unstable(feature = "generator_trait", issue = "43122")]
 impl<G: ?Sized + Generator<R>, R> Generator<R> for Pin<&mut G> {
     type Yield = G::Yield;
@@ -149,7 +123,6 @@ impl<G: ?Sized + Generator<R>, R> Generator<R> for Pin<&mut G> {
     }
 }
 
-#[cfg(not(bootstrap))]
 #[unstable(feature = "generator_trait", issue = "43122")]
 impl<G: ?Sized + Generator<R> + Unpin, R> Generator<R> for &mut G {
     type Yield = G::Yield;
diff --git a/src/libcore/prelude/v1.rs b/src/libcore/prelude/v1.rs
index 66b5a90b77b..c91370b2719 100644
--- a/src/libcore/prelude/v1.rs
+++ b/src/libcore/prelude/v1.rs
@@ -67,3 +67,12 @@ pub use crate::{
 pub use crate::macros::builtin::{
     bench, global_allocator, test, test_case, RustcDecodable, RustcEncodable,
 };
+
+#[cfg(not(bootstrap))]
+#[unstable(
+    feature = "cfg_accessible",
+    issue = "64797",
+    reason = "`cfg_accessible` is not fully implemented"
+)]
+#[doc(no_inline)]
+pub use crate::macros::builtin::cfg_accessible;