100/100 regression tests pass (+ffi-objc-call-02-void-return xfail
snapshot).
The intrinsic with no `inline if false` guard reaches sema/codegen
and trips an "unresolved: 'unknown_expr'" — the FfiIntrinsicCall
AST node from Phase 1.1 has no lowering rules in lower.zig /
emit_llvm.zig yet.
nil receiver was chosen so the test doesn't need a real Obj-C
object graph: the runtime guarantees `[nil msg]` is a no-op with
zero result for void returns. macOS-gated via `inline if OS == .macos`
so the runner stays portable.
Next commit: emit_llvm.zig produces the per-call-site
%sel = call ptr @sel_registerName(ptr "init.0")
call void @objc_msgSend(ptr null, ptr %sel)
lowering. Snapshot flips to "ok". Selector interning (one shared
global per unique selector string) lands as a separate step (1.5).