chore(deps): bump rust-toolchain from 1.91 to 1.93

[dependabot]

Bumps rust-toolchain from 1.91 to 1.93.

Release notes

Sourced from rust-toolchain's releases.

Rust 1.93.0

Language

• Stabilize several s390x vector-related target features and the is_s390x_feature_detected! macro
• Stabilize declaration of C-style variadic functions for the system ABI
• Emit error when using some keyword as a cfg predicate
• Stabilize asm_cfg
• During const-evaluation, support copying pointers byte-by-byte
• LUB coercions now correctly handle function item types, and functions with differing safeties
• Allow const items that contain mutable references to static (which is very unsafe, but not always UB)
• Add warn-by-default const_item_interior_mutations lint to warn against calls which mutate interior mutable const items
• Add warn-by-default function_casts_as_integer lint

Compiler

• Stabilize -Cjump-tables=bool. The flag was previously called -Zno-jump-tables.

Platform Support

• Promote riscv64a23-unknown-linux-gnu to Tier 2 (without host tools)

Refer to Rust's platform support page for more information on Rust's tiered platform support.

Libraries

• Stop internally using specialization on the Copy trait as it is unsound in the presence of lifetime dependent Copy implementations. This may result in some performance regressions as some standard library APIs may now call Clone::clone instead of performing bitwise copies
• Allow the global allocator to use thread-local storage and std::thread::current()
• Make BTree::append not update existing keys when appending an entry which already exists
• Don't require T: RefUnwindSafe for vec::IntoIter<T>: UnwindSafe

Stabilized APIs

• <[MaybeUninit<T>]>::assume_init_drop
• <[MaybeUninit<T>]>::assume_init_ref
• <[MaybeUninit<T>]>::assume_init_mut
• <[MaybeUninit<T>]>::write_copy_of_slice
• <[MaybeUninit<T>]>::write_clone_of_slice
• String::into_raw_parts
• Vec::into_raw_parts
• <iN>::unchecked_neg

... (truncated)

Changelog

Sourced from rust-toolchain's changelog.

Version 1.93.0 (2026-01-22)

Language

• Stabilize several s390x vector-related target features and the is_s390x_feature_detected! macro
• Stabilize declaration of C-style variadic functions for the system ABI
• Emit error when using some keyword as a cfg predicate
• Stabilize asm_cfg
• During const-evaluation, support copying pointers byte-by-byte
• LUB coercions now correctly handle function item types, and functions with differing safeties
• Allow const items that contain mutable references to static (which is very unsafe, but not always UB)
• Add warn-by-default const_item_interior_mutations lint to warn against calls which mutate interior mutable const items
• Add warn-by-default function_casts_as_integer lint

Compiler

• Stabilize -Cjump-tables=bool. The flag was previously called -Zno-jump-tables.

Platform Support

• Promote riscv64a23-unknown-linux-gnu to Tier 2 (without host tools)

Refer to Rust's platform support page for more information on Rust's tiered platform support.

Libraries

• Stop internally using specialization on the Copy trait as it is unsound in the presence of lifetime dependent Copy implementations. This may result in some performance regressions as some standard library APIs may now call Clone::clone instead of performing bitwise copies
• Allow the global allocator to use thread-local storage and std::thread::current()
• Make BTree::append not update existing keys when appending an entry which already exists
• Don't require T: RefUnwindSafe for vec::IntoIter<T>: UnwindSafe

Stabilized APIs

... (truncated)

Commits

• 254b596 Auto merge of #151369 - Mark-Simulacrum:stable-next, r=Mark-Simulacrum
• 01ad1d6 Bump to stable release
• 641c209 Add latest release note copy
• a741008 Auto merge of #151270 - Mark-Simulacrum:beta-backport, r=Mark-Simulacrum
• 6feceec Disable SimplifyComparisonIntegral
• 2b8a999 Use both bors e-mails for CI postprocessing git lookup
• 4c28b43 Revert bors email to the original homu one
• a8201d3 Remove references to bors2
• 9a4aba1 Auto merge of #151241 - fmease:beta-rustdoc-dont-eval-assoc-consts, r=fmease
• 36e6625 [beta] rustdoc: Stop unconditionally evaluating the initializer of associated...
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