Auto merge of #161458 - jhpratt:rollup-q1wVzyt, r=jhpratt

Rollup of 20 pull requests

Successful merges:

 - rust-lang/rust#161259 (move some attribute related structs out of rustc_attr_ir)
 - rust-lang/rust#160853 (delegation: simplify matches on `FnKind`, minor refactorings)
 - rust-lang/rust#161161 (proc_macro: add support for 16-bit targets)
 - rust-lang/rust#159899 ( `GenericArgs::types` triage + possible fixes)
 - rust-lang/rust#160459 (Use attribute parser for `deprecated` attribute checking)
 - rust-lang/rust#160536 (Inline `String::into_raw_parts` and reuse `from_utf16` optimization)
 - rust-lang/rust#160563 (Make `BorrowedCursor<'a, T>` covariant in `'a` and drop an indirection)
 - rust-lang/rust#160595 (Clarify `str::split_at` docs)
 - rust-lang/rust#160813 (Optimize linked list iterator performance)
 - rust-lang/rust#161271 (doc: document safety requirements for core WTF-8)
 - rust-lang/rust#161317 (LLVM 24: configure float-abi via module flag)
 - rust-lang/rust#161320 (Only suggest `RUST_MIN_STACK` if maybe stack overflow)
 - rust-lang/rust#161369 (Add regression test for confusing lifetime error message issue)
 - rust-lang/rust#161393 (Configure LLM policy URL for triagebot)
 - rust-lang/rust#161403 (splat-fn-ptr-ptr-tuple.rs: add `let` to avoid UB)
 - rust-lang/rust#161409 (Add back `tests/rustdoc-gui/notable-trait.goml` test)
 - rust-lang/rust#161410 (Fix rustdoc remapping `documentation` scope documentation)
 - rust-lang/rust#161415 (Update expect messages in path docs to better follow guidelines)
 - rust-lang/rust#161438 (Change triagebot backport to ping T-libs-fcp)
 - rust-lang/rust#161442 (Add regression test for dead code on type alias used in impl self type)

Failed merges:

 - rust-lang/rust#160509 (Remove `RegionExt`; move methods to `Region` in `rustc_type_ir`)