bump Rust version and add patch for IntoIter issue

Author: RalfJung

rust-src.diff

@@ -0,0 +1,53 @@
+diff --git a/library/alloc/src/vec/into_iter.rs b/library/alloc/src/vec/into_iter.rs
+index 6bcde6d899c..cd4ea829e37 100644
+--- a/library/alloc/src/vec/into_iter.rs
++++ b/library/alloc/src/vec/into_iter.rs
+@@ -40,7 +40,9 @@ pub struct IntoIter<
+     // to avoid dropping the allocator twice we need to wrap it into ManuallyDrop
+     pub(super) alloc: ManuallyDrop<A>,
+     pub(super) ptr: *const T,
+-    pub(super) end: *const T,
++    pub(super) end: *const T, // If T is a ZST, this is actually ptr+len.  This encoding is picked so that
++                              // ptr == end is a quick test for the Iterator being empty, that works
++                              // for both ZST and non-ZST.
+ }
+ 
+ #[stable(feature = "vec_intoiter_debug", since = "1.13.0")]
+@@ -132,7 +134,9 @@ pub(super) fn forget_allocation_drop_remaining(&mut self) {
+ 
+     /// Forgets to Drop the remaining elements while still allowing the backing allocation to be freed.
+     pub(crate) fn forget_remaining_elements(&mut self) {
+-        self.ptr = self.end;
++        // For th ZST case, it is crucial that we mutate `end` here, not `ptr`.
++        // `ptr` must stay aligned, while `end` may be unaligned.
++        self.end = self.ptr;
+     }
+ 
+     #[cfg(not(no_global_oom_handling))]
+@@ -184,10 +188,9 @@ fn next(&mut self) -> Option<T> {
+         if self.ptr == self.end {
+             None
+         } else if T::IS_ZST {
+-            // purposefully don't use 'ptr.offset' because for
+-            // vectors with 0-size elements this would return the
+-            // same pointer.
+-            self.ptr = self.ptr.wrapping_byte_add(1);
++            // `ptr` has to stay where it is to remain aligned, so we reduce the length by 1 by
++            // reducing the `end`.
++            self.end = self.end.wrapping_byte_sub(1);
+ 
+             // Make up a value of this ZST.
+             Some(unsafe { mem::zeroed() })
+@@ -214,10 +217,8 @@ fn advance_by(&mut self, n: usize) -> Result<(), usize> {
+         let step_size = self.len().min(n);
+         let to_drop = ptr::slice_from_raw_parts_mut(self.ptr as *mut T, step_size);
+         if T::IS_ZST {
+-            // SAFETY: due to unchecked casts of unsigned amounts to signed offsets the wraparound
+-            // effectively results in unsigned pointers representing positions 0..usize::MAX,
+-            // which is valid for ZSTs.
+-            self.ptr = self.ptr.wrapping_byte_add(step_size);
++            // See `next` for why we sub `end` here.
++            self.end = self.end.wrapping_byte_sub(step_size);
+         } else {
+             // SAFETY: the min() above ensures that step_size is in bounds
+             self.ptr = unsafe { self.ptr.add(step_size) };

rust-version

@@ -1 +1 @@
-nightly-2022-11-24
+nightly-2022-12-23