Static dispatch wired in. The early `is_static` bail in
`.jni_msg_send` is gone; both paths now share the same lazy-cache +
phi structure with two static-specific differences:
1. `GetObjectClass` is skipped — for static calls, `target` IS the
`jclass`. The cached `cls` slot just stores `NewGlobalRef(target)`
directly.
2. The method-ID lookup uses `GetStaticMethodID` (slot 113), and the
dispatch uses `CallStatic<Type>Method` (Object 114 / Boolean 117
/ Int 129 / Long 132 / Float 135 / Double 138 / Void 141).
Slot interning still applies: the `@SX_JNI_{CLS,MID}_<key>` pair is
shared between instance and static literal call sites with the same
`(name, sig)` — though in practice the JNI runtime treats instance
and static method-IDs as distinct, so two sites with the same name
but different dispatch kinds would collide in the cache. This isn't
a problem the chess Android backend hits (each method is uniquely
either static or instance in the API), so the simpler single-key
intern stays.
IR snapshot updated: `ret i32 undef` replaced by the full
NewGlobalRef → GetStaticMethodID → CallStaticIntMethod sequence
through vtable slots 21, 113, 129. Args `i32 3, i32 7` thread through
the existing arg-coercion loop.
7b566bfb83