Rust for Mac1.54.0

Language:

• You can now use macros for values in built-in attribute macros. While a seemingly minor addition on its own, this enables a lot of powerful functionality when combined correctly. Most notably you can now include external documentation in your crate by writing the following: #![doc = include_str!("README.md")]
• You can also use this to include auto-generated modules: #[path = concat!(env!("OUT_DIR"), "/generated.rs")] mod generated;
• You can now cast between unsized slice types (and types which contain unsized slices) in const fn.
• You can now use multiple generic lifetimes with impl Trait where the lifetimes don't explicitly outlive another. In code this means that you can now have impl Trait where as before you could only have impl Trait where 'b: 'a.

Compiler:

• Rustc will now search for custom JSON targets in /lib/rustlib//target.json where / is the "sysroot" directory. You can find your sysroot directory by running rustc --print sysroot.
• Added wasm as a target_family for WebAssembly platforms.
• You can now use #[target_feature] on safe functions when targeting WebAssembly platforms.
• Improved debugger output for enums on Windows MSVC platforms.
• Added tier 3* support for bpfel-unknown-none and bpfeb-unknown-none.
• * Refer to Rust's platform support page for more information on Rust's tiered platform support.

Libraries:

• panic::panic_any will now #[track_caller].
• Added OutOfMemory as a variant of io::ErrorKind.
• proc_macro::Literal now implements FromStr.
• The implementations of vendor intrinsics in core::arch have been significantly refactored. The main user-visible changes are a 50% reduction in the size of libcore.rlib and stricter validation of constant operands passed to intrinsics. The latter is technically a breaking change, but allows Rust to more closely match the C vendor intrinsics API.

Stabilized APIs:

• BTreeMap::into_keys
• BTreeMap::into_values
• HashMap::into_keys
• HashMap::into_values
• arch::wasm32
• VecDeque::binary_search
• VecDeque::binary_search_by
• VecDeque::binary_search_by_key
• VecDeque::partition_point

Cargo:

• Added the --prune option to cargo-tree to remove a package from the dependency graph.
• Added the --depth option to cargo-tree to print only to a certain depth in the tree
• Added the no-proc-macro value to cargo-tree --edges to hide procedural macro dependencies.
• A new environment variable named CARGO_TARGET_TMPDIR is available. This variable points to a directory that integration tests and benches can use as a "scratchpad" for testing filesystem operations.

Compatibility Notes:

• Mixing Option and Result via ? is no longer permitted in closures for inferred types.
• Previously unsound code is no longer permitted where different constructors in branches could require different lifetimes.
• As previously mentioned the std::arch instrinsics now uses stricter const checking than before and may reject some previously accepted code.
• i128 multiplication on Cortex M0+ platforms currently unconditionally causes overflow when compiled with codegen-units = 1.