CI e2e-scoped: typed_array_rmw_8692 'module compiles' panics on unrelated PRs, passes 9/9 locally #11350

CI's e2e-scoped job fails cargo test -p perry-codegen --test typed_array_rmw_8692 on unrelated PRs:

• perf(codegen): bind an object-literal method's this once and read its fields through the literal's shape class (#10906) #11326 (merged with this failure)
• perf(runtime): [[Prototype]] is part of shape identity; store sites prove their chain once #11342

The failing case is specialized_uint32_dynamic_index_rmw_has_a_call_free_fast_arm_and_fallback, which panics at crates/perry-codegen/tests/typed_array_rmw_8692.rs:122 (.expect("module compiles")). The other 8 cases pass.

Neither PR touches that test or the typed-array RMW lowering. On a Linux x86_64 host (Rust nightly-2026-08-20, LLVM 22.1.8), the test passes 9/9 on both the PR head and its merge-base: in release, in debug, and in 8 repeated parallel runs. So the module fails to compile only in CI's environment. Possible causes include CI's LLVM or libc, runner resources, or a race in how the test sets up its temporary compile.

Recent main runs show e2e-scoped: skipped, so main itself doesn't exercise this job. That is presumably why nothing on main flags it.