ffi 2.11 xfail: DSL call site on #jni_class-typed receiver

`act.getWindow()` on `act: *Activity` (where `Activity ::
#jni_class("android/app/Activity") { getWindow :: ... }`) should
lower to `#jni_call(*void)(act, "getWindow", "()Ljava/lang/Object;")`
(omitted-env form picking up env from the enclosing `#jni_env`
scope via 2.16b's lexical-direct path). Today's sema reports
"unresolved: 'getWindow'" because foreign-class members aren't
yet wired into the method-resolution path.

The make-green follow-up needs:
  - sema: register `ForeignClassDecl.members` so method names
    resolve on foreign-class receivers (or suppress the unresolved
    fallback for them).
  - lower: build a `foreign_class_map` in scan pass; new arm in
    `lowerCall`'s method-dispatch site emits a synthetic
    `FfiIntrinsicCall { kind: jni_call, args: [target, "name",
    "(sig)Ret", method_args...] }` with the descriptor derived via
    `jni_descriptor.deriveMethod`.
  - type system: `*Activity` resolution path so `inferExprType`
    on the receiver returns a known type (likely register foreign
    classes as synthetic 0-field structs reusing the struct-type
    machinery).

Larger session needed — pausing here at the xfail.

tests/expected/ffi-jni-class-08-call.exit

@@ -0,0 +1 @@
+1

tests/expected/ffi-jni-class-08-call.txt

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+/Users/agra/projects/sx/examples/ffi-jni-class-08-call.sx:21:16: error: unresolved: 'getWindow'