Auto merge of #146666 - Zalathar:rollup-m2b8low, r=Zalathar

Rollup of 14 pull requests

Successful merges:

 - rust-lang/rust#142807 (libtest: expose --fail-fast as an unstable command-line option)
 - rust-lang/rust#144871 (Stabilize `btree_entry_insert` feature)
 - rust-lang/rust#145071 (Update the minimum external LLVM to 20)
 - rust-lang/rust#145181 (remove FIXME block from `has_significant_drop`, it never encounters inference variables)
 - rust-lang/rust#145660 (initial implementation of the darwin_objc unstable feature)
 - rust-lang/rust#145838 (don't apply temporary lifetime extension rules to non-extended `super let`)
 - rust-lang/rust#146259 (Suggest removing Box::new instead of unboxing it)
 - rust-lang/rust#146410 (Iterator repeat: no infinite loop for `last` and `count`)
 - rust-lang/rust#146460 (Add tidy readme)
 - rust-lang/rust#146552 (StateTransform: Do not renumber resume local.)
 - rust-lang/rust#146564 (Remove Rvalue::Len again.)
 - rust-lang/rust#146581 (Detect attempt to use var-args in closure)
 - rust-lang/rust#146588 (tests/run-make: Update list of statically linked musl targets)
 - rust-lang/rust#146631 (cg_llvm: Replace some DIBuilder wrappers with LLVM-C API bindings (part 3))

r? `@ghost`
`@rustbot` modify labels: rollup

Author: bors

clippy_utils/src/qualify_min_const_fn.rs

@@ -126,7 +126,7 @@ fn check_rvalue<'tcx>(
 ) -> McfResult {
     match rvalue {
         Rvalue::ThreadLocalRef(_) => Err((span, "cannot access thread local storage in const fn".into())),
-        Rvalue::Len(place) | Rvalue::Discriminant(place) | Rvalue::Ref(_, _, place) | Rvalue::RawPtr(_, place) => {
+        Rvalue::Discriminant(place) | Rvalue::Ref(_, _, place) | Rvalue::RawPtr(_, place) => {
             check_place(cx, *place, span, body, msrv)
         },
         Rvalue::CopyForDeref(place) => check_place(cx, *place, span, body, msrv),