Merge train: #9916, #9920

[proggeramlug]

Merge train: #9916, #9920.

The one real merge: #9916 against #9914

#9914 landed in #9922 minutes earlier, and both PRs rewrite the same node:test reporter output lines from different directions — #9914 adds SKIP markers and directive suffixes, #9916 adds nesting and indentation. Neither side's version is correct on its own, so the spec-reporter test:pass arm and the TAP ok line are hand-merged to carry both: parent ▶ lines and event_indent, and the ﹣/✔ marker with spec_directive_suffix / directive_suffix.

Checked by asserting all eight distinguishing behaviours are present in the merged file rather than settling for a clean compile — the helper pair from each PR, the SKIP marker, both suffix call sites, the parent-line drain, and the indent on both the spec pass line and the TAP ok line.

#9920

Two changes, both minimal. parser.problem gets an explicit .cast::<std::ffi::c_char>(), which is the portable spelling — c_char is u8 on ARM Linux and i8 on x86. And gc-native-roots.yml stops overriding LLVM_SYS_221_PREFIX with brew --prefix llvm, keeping the value setup-llvm22 provides: the stock-toolchain assertion removes the external opt/clang overrides, but llvm-sys still has to link the LLVM 22 ABI.

Validation

run_lint_gates: all 64 gates passed; 2 CI-only skipped

suite	passed	failed
perry-runtime	3262	0
perry-codegen	1940	0
perry-hir	628	0
perry-stdlib	132	0