Auto merge of #155674 - JonathanBrouwer:rollup-NG1fnzG, r=JonathanBrouwer

Rollup of 10 pull requests

Successful merges:

 - rust-lang/rust#146544 (mir-opt: Remove the workaround in UnreachableEnumBranching)
 - rust-lang/rust#154819 (Fix ICE for inherent associated type mismatches)
 - rust-lang/rust#155265 (Improved assumptions relating to isqrt)
 - rust-lang/rust#152576 (c-variadic: use `emit_ptr_va_arg` for  mips)
 - rust-lang/rust#154481 (Mark a function only used in nightly as nightly only)
 - rust-lang/rust#155614 (c-variadic: rename `VaList::arg` to `VaList::next_arg`)
 - rust-lang/rust#155630 (Make `//@ skip-filecheck` a normal compiletest directive)
 - rust-lang/rust#155641 (Remove non-working code for "running" mir-opt tests)
 - rust-lang/rust#155652 (Expand `Path::is_empty` docs)
 - rust-lang/rust#155656 (rustc_llvm: update opt-level handling for LLVM 23)