Three pieces, no behavior change yet:
1. `ObjcPropertyKind` enum (strong/weak/copy/assign) + `objcPropertyKind`
helper in lower.zig. Reads `field.property_modifiers`, applies the
default rule (`*<ObjC-class>` → strong; primitives → assign), and
emits loud diagnostics for the silent-error budget:
- unknown modifier name (typo) → "expected one of: strong, weak, copy, ..."
- conflicting modifiers (e.g. `strong,weak`) → "mutually exclusive"
- `weak` on non-object slot → "requires a pointer-to-Obj-C-class type"
- `copy` on non-object slot → same
- `strong` (default or explicit) on `*void` → "ambiguous: specify
#property(strong|weak|copy|assign) explicitly"
Called from `emitObjcDefinedClassPropertyImps` for validation; the
returned kind isn't wired into setter/getter/dealloc yet — that's
the next three commits.
2. `ensureArcRuntimeDecls` lazily declares libobjc's ARC helpers:
objc_retain, objc_release, objc_storeWeak, objc_loadWeakRetained,
objc_initWeak, objc_destroyWeak. Uses the existing
`ensureCRuntimeDecl` pattern; idempotent.
3. Fix existing NSObject method names in std/objc.sx — `isEqual_`,
`isKindOfClass_`, `respondsToSelector_` had trailing underscores
that the selector mangling turned into double-colon selectors
(`isEqual::`). Removed the trailing underscore so the selectors
come out as `isEqual:`, `isKindOfClass:`, `respondsToSelector:`
as Apple's runtime expects.
4. Two xfail regression tests:
- ffi-objc-arc-02-strong-property: assigns child to parent's strong
property, releases the original child reference. Midpoint check:
child's dealloc should NOT have fired (strong setter retained).
Pre-M4.B-setter: child dealloc fires immediately → "FAIL: child
dealloc'd at midpoint" snapshot. Exit code 1.
- ffi-objc-arc-03-weak-property: assigns target to holder's weak
property, releases target. Reads holder.target → should be null
(auto-niled). Pre-M4.B-getter/setter: reads stale pointer →
"FAIL: weak property didn't auto-nil" snapshot.
These will turn green as M4.B setter (commit 2), getter (commit 3),
and dealloc-cleanup (commit 4) land. Each subsequent commit updates
the snapshot to reflect the now-passing output.
189/189 example tests pass; chess on iOS-sim green.
5c1d00a877